diff --git a/VERSION b/VERSION
index 054dfe3..95a5509 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.1.0.beta2
+1.1.0.beta3
diff --git a/benchmarks/dirty.rb b/benchmarks/dirty.rb
index d5ffe2e..644f84d 100644
--- a/benchmarks/dirty.rb
+++ b/benchmarks/dirty.rb
@@ -111,8 +111,8 @@ begin
       run_benchmark
     end
     set_dirty(false)
+    puts "\nwith use_dirty false"
   end
   
-  puts "\nwith use_dirty false"
   run_benchmark
 end
diff --git a/history.txt b/history.txt
index 15059c6..49aa82b 100644
--- a/history.txt
+++ b/history.txt
@@ -1,6 +1,7 @@
 == 1.1.0.beta3
 
 * Major changes:
+  * Fast Dirty Tracking! Many thanks to @sobakasu (Andrew Williams)
   * Default CouchRest Model type field now set to 'model' instead of 'couchrest-type'.
 
 * Minor enhancements:
diff --git a/lib/couchrest/model/base.rb b/lib/couchrest/model/base.rb
index 3e585cc..b3b1b17 100644
--- a/lib/couchrest/model/base.rb
+++ b/lib/couchrest/model/base.rb
@@ -40,10 +40,6 @@ module CouchRest
         subclasses << subklass
       end
 
-      # Accessors
-      attr_accessor :casted_by
-
-
       # Instantiate a new CouchRest::Model::Base by preparing all properties
       # using the provided document hash.
       #
diff --git a/lib/couchrest/model/casted_model.rb b/lib/couchrest/model/casted_model.rb
index 4679954..990f454 100644
--- a/lib/couchrest/model/casted_model.rb
+++ b/lib/couchrest/model/casted_model.rb
@@ -11,31 +11,31 @@ module CouchRest::Model
       include CouchRest::Model::Associations
       include CouchRest::Model::Validations
       include CouchRest::Model::Dirty
-      attr_accessor :casted_by
+      # attr_accessor :casted_by
     end
-    
+
     def initialize(keys = {})
       raise StandardError unless self.is_a? Hash
       prepare_all_attributes(keys)
       super()
     end
-    
+
     def []= key, value
-      couchrest_attribute_will_change!(key) if use_dirty && self[key] != value
+      couchrest_attribute_will_change!(key) if self[key] != value
       super(key.to_s, value)
     end
-    
+
     def [] key
       super(key.to_s)
     end
-    
+
     # Gets a reference to the top level extended
     # document that a model is saved inside of
     def base_doc
       return nil unless @casted_by
       @casted_by.base_doc
     end
-    
+
     # False if the casted model has already
     # been saved in the containing document
     def new?
diff --git a/lib/couchrest/model/configuration.rb b/lib/couchrest/model/configuration.rb
index e68c53d..027bf3c 100644
--- a/lib/couchrest/model/configuration.rb
+++ b/lib/couchrest/model/configuration.rb
@@ -11,13 +11,11 @@ module CouchRest
         add_config :model_type_key
         add_config :mass_assign_any_attribute
         add_config :auto_update_design_doc
-        add_config :use_dirty
 
         configure do |config|
           config.model_type_key = 'model' # was 'couchrest-type'
           config.mass_assign_any_attribute = false
           config.auto_update_design_doc = true
-          config.use_dirty = true
         end
       end
 
diff --git a/lib/couchrest/model/dirty.rb b/lib/couchrest/model/dirty.rb
index e0a13b0..ef74e72 100644
--- a/lib/couchrest/model/dirty.rb
+++ b/lib/couchrest/model/dirty.rb
@@ -22,7 +22,7 @@ module CouchRest
 
       def use_dirty?
         bdoc = base_doc
-        bdoc && bdoc.use_dirty && !bdoc.disable_dirty
+        bdoc && !bdoc.disable_dirty
       end
 
       def couchrest_attribute_will_change!(attr)
@@ -30,13 +30,13 @@ module CouchRest
         attribute_will_change!(attr)
         couchrest_parent_will_change!
       end
-      
+
       def couchrest_parent_will_change!
         @casted_by.couchrest_attribute_will_change!(casted_by_attribute) if @casted_by
       end
 
       private
-      
+
       # return the attribute name this object is referenced by in the parent
       def casted_by_attribute
         return @casted_by_attribute if @casted_by_attribute
diff --git a/lib/couchrest/model/persistence.rb b/lib/couchrest/model/persistence.rb
index 7679f8d..6374722 100644
--- a/lib/couchrest/model/persistence.rb
+++ b/lib/couchrest/model/persistence.rb
@@ -30,7 +30,7 @@ module CouchRest
       def update(options = {})
         raise "Calling #{self.class.name}#update on document that has not been created!" if self.new?
         return false unless perform_validations(options)
-        return true if use_dirty? && !self.changed?
+        return true if !self.changed?
         _run_update_callbacks do
           _run_save_callbacks do
             result = database.save_doc(self)
diff --git a/lib/couchrest/model/properties.rb b/lib/couchrest/model/properties.rb
index 3c32b78..5e0e356 100644
--- a/lib/couchrest/model/properties.rb
+++ b/lib/couchrest/model/properties.rb
@@ -6,9 +6,9 @@ module CouchRest
 
       included do
         extlib_inheritable_accessor(:properties) unless self.respond_to?(:properties)
-        extlib_inheritable_accessor(:prop_by_name) unless self.respond_to?(:prop_by_name)
+        extlib_inheritable_accessor(:property_by_name) unless self.respond_to?(:property_by_name)
         self.properties ||= []
-        self.prop_by_name ||= {}
+        self.property_by_name ||= {}
         raise "You can only mixin Properties in a class responding to [] and []=, if you tried to mixin CastedModel, make sure your class inherits from Hash or responds to the proper methods" unless (method_defined?(:[]) && method_defined?(:[]=))
       end
 
@@ -39,19 +39,12 @@ module CouchRest
       end
 
       # Store a casted value in the current instance of an attribute defined
-      # with a property.
+      # with a property and update dirty status
       def write_attribute(property, value)
-        prop = find_property!(property)
-        self[prop.to_s] = prop.is_a?(String) ? value : prop.cast(self, value)
-      end
-
-      # write property, update dirty status
-      def write_attribute_dirty(property, value)
         prop = find_property!(property)
         value = prop.is_a?(String) ? value : prop.cast(self, value)
-        propname = prop.to_s
-        attribute_will_change!(propname) if use_dirty? && self[propname] != value
-        self[propname] = value
+        attribute_will_change!(prop.name) if use_dirty? && self[prop.name] != value
+        self[prop.name] = value
       end
 
       def []=(key,value)
@@ -82,34 +75,47 @@ module CouchRest
         # Remove any protected and update all the rest. Any attributes
         # which do not have a property will simply be ignored.
         attrs = remove_protected_attributes(hash)
-        directly_set_attributes(attrs, :dirty => true)
+        directly_set_attributes(attrs)
       end
       alias :attributes= :update_attributes_without_saving
 
       # 'attributes' needed for Dirty
       alias :attributes :properties_with_values
 
+      def set_attributes(hash)
+        attrs = remove_protected_attributes(hash)
+        directly_set_attributes(attrs)
+      end
+
+      protected
+
       def find_property(property)
-        property.is_a?(Property) ? property : self.class.prop_by_name[property.to_s]
+        property.is_a?(Property) ? property : self.class.property_by_name[property.to_s]
       end
 
       # The following methods should be accessable by the Model::Base Class, but not by anything else!
       def apply_all_property_defaults
         return if self.respond_to?(:new?) && (new? == false)
         # TODO: cache the default object
+        # Never mark default options as dirty!
+        dirty, self.disable_dirty = self.disable_dirty, true
         self.class.properties.each do |property|
           write_attribute(property, property.default_value)
         end
+        self.disable_dirty = dirty
       end
 
       def prepare_all_attributes(doc = {}, options = {})
+        self.disable_dirty = !!options[:directly_set_attributes]
         apply_all_property_defaults
         if options[:directly_set_attributes]
           directly_set_read_only_attributes(doc)
         else
           doc = remove_protected_attributes(doc)
         end
-        directly_set_attributes(doc) unless doc.nil?
+        res = doc.nil? ? doc : directly_set_attributes(doc)
+        self.disable_dirty = false
+        res
       end
 
       def find_property!(property)
@@ -120,9 +126,8 @@ module CouchRest
 
       # Set all the attributes and return a hash with the attributes
       # that have not been accepted.
-      def directly_set_attributes(hash, options = {})
-        self.disable_dirty = !options[:dirty]
-        ret = hash.reject do |attribute_name, attribute_value|
+      def directly_set_attributes(hash)
+        hash.reject do |attribute_name, attribute_value|
           if self.respond_to?("#{attribute_name}=")
             self.send("#{attribute_name}=", attribute_value)
             true
@@ -133,8 +138,6 @@ module CouchRest
             false
           end
         end
-        self.disable_dirty = false
-        ret
       end
 
       def directly_set_read_only_attributes(hash)
@@ -147,10 +150,6 @@ module CouchRest
         end
       end
 
-      def set_attributes(hash)
-        attrs = remove_protected_attributes(hash)
-        directly_set_attributes(attrs)
-      end
 
 
       module ClassMethods
@@ -206,14 +205,14 @@ module CouchRest
               end
               type = [type] # inject as an array
             end
-            property = Property.new(name, type, options.merge(:use_dirty => use_dirty))
+            property = Property.new(name, type, options)
             create_property_getter(property)
             create_property_setter(property) unless property.read_only == true
             if property.type_class.respond_to?(:validates_casted_model)
               validates_casted_model property.name
             end
             properties << property
-            prop_by_name[property.to_s] = property
+            property_by_name[property.to_s] = property
             property
           end
 
@@ -247,7 +246,7 @@ module CouchRest
             property_name = property.name
             class_eval <<-EOS
               def #{property_name}=(value)
-                write_attribute_dirty('#{property_name}', value)
+                write_attribute('#{property_name}', value)
               end
             EOS
 
diff --git a/lib/couchrest/model/property.rb b/lib/couchrest/model/property.rb
index 783cc69..4af8864 100644
--- a/lib/couchrest/model/property.rb
+++ b/lib/couchrest/model/property.rb
@@ -4,7 +4,7 @@ module CouchRest::Model
 
     include ::CouchRest::Model::Typecast
 
-    attr_reader :name, :type, :type_class, :read_only, :alias, :default, :casted, :init_method, :use_dirty, :options
+    attr_reader :name, :type, :type_class, :read_only, :alias, :default, :casted, :init_method, :options
 
     # Attribute to define.
     # All Properties are assumed casted unless the type is nil.
@@ -38,8 +38,8 @@ module CouchRest::Model
         end
         arr = value.collect { |data| cast_value(parent, data) }
         # allow casted_by calls to be passed up chain by wrapping in CastedArray
-        value = (use_dirty || type_class != String) ? CastedArray.new(arr, self) : arr
-        value.casted_by = parent if value.respond_to?(:casted_by)
+        value = CastedArray.new(arr, self)
+        value.casted_by = parent
       elsif (type == Object || type == Hash) && (value.class == Hash)
         # allow casted_by calls to be passed up chain by wrapping in CastedHash
         value = CouchRest::Model::CastedHash[value]
@@ -94,7 +94,6 @@ module CouchRest::Model
         @alias              = options.delete(:alias)      if options[:alias]
         @default            = options.delete(:default)    unless options[:default].nil?
         @init_method        = options[:init_method] ? options.delete(:init_method) : 'new'
-        @use_dirty          = options.delete(:use_dirty)
         @options            = options
       end
 
diff --git a/spec/couchrest/dirty_spec.rb b/spec/couchrest/dirty_spec.rb
index cf47aeb..990cb7a 100644
--- a/spec/couchrest/dirty_spec.rb
+++ b/spec/couchrest/dirty_spec.rb
@@ -14,88 +14,25 @@ class WithCastedModelMixin < Hash
 end 
 
 class DummyModel < CouchRest::Model::Base
-  use_database TEST_SERVER.default_database
-  raise "Default DB not set" if TEST_SERVER.default_database.nil?
+  use_database DB
+
   property :casted_attribute, WithCastedModelMixin
+  property :title, :default => 'Sample Title'
   property :details,     Object,   :default => { 'color' => 'blue' }
   property :keywords,    [String], :default => ['default-keyword']
-  property :sub_models do |child|
-    child.property :title
+  property :sub_models do
+    property :title
   end
 end
 
-# set dirty configuration, return previous configuration setting
-def set_dirty(value)
-  orig = nil
-  CouchRest::Model::Base.configure do |config|
-    orig = config.use_dirty
-    config.use_dirty = value
-  end
-  Card.instance_eval do
-    self.use_dirty = value
-  end
-  orig
-end
-
-describe "With use_dirty(off)" do
-
-  before(:all) do
-    @use_dirty_orig = set_dirty(false)
-  end
-
-  # turn dirty back to default
-  after(:all) do
-    set_dirty(@use_dirty_orig)
-  end
-
-  describe "changes" do
-    
-    it "should not respond to the changes method" do
-      @card = Card.new
-      @card.first_name = "andrew"
-      @card.changes.should == {}
-    end
-
-  end
-
-  describe "changed?" do
-
-    it "should not record changes" do
-      @card = Card.new
-      @card.first_name = "andrew"
-      @card.changed?.should be_false
-    end
-  end
-
-  describe "save" do
-    
-    it "should save unchanged records" do
-      @card = Card.create!(:first_name => "matt")
-      @card = Card.find(@card.id)
-      @card.database.should_receive(:save_doc).and_return({"ok" => true})
-      @card.save
-    end
-
-  end
-
-end
-
-describe "With use_dirty(on)" do
-
-  before(:all) do
-    @use_dirty_orig = set_dirty(true)
-  end
-
-  # turn dirty back to default
-  after(:all) do
-    set_dirty(@use_dirty_orig)
-  end
+describe "Dirty" do
 
   describe "changes" do
 
     it "should return changes on an attribute" do
       @card = Card.new(:first_name => "matt")
       @card.first_name = "andrew"
+      @card.first_name_changed?.should be_true
       @card.changes.should == { "first_name" => ["matt", "andrew"] }
     end
 
diff --git a/spec/couchrest/property_spec.rb b/spec/couchrest/property_spec.rb
index 5d21079..a8c81b9 100644
--- a/spec/couchrest/property_spec.rb
+++ b/spec/couchrest/property_spec.rb
@@ -357,10 +357,10 @@ describe "Property Class" do
       property.cast(parent, ["2010-06-01", "2010-06-02"]).class.should eql(CouchRest::Model::CastedArray)
     end
 
-    it "should not set a CastedArray on array of Strings" do
+    it "should set a CastedArray on array of Strings" do
       property = CouchRest::Model::Property.new(:test, [String])
       parent = mock("FooObject")
-      property.cast(parent, ["2010-06-01", "2010-06-02"]).class.should_not eql(CouchRest::Model::CastedArray)
+      property.cast(parent, ["2010-06-01", "2010-06-02"]).class.should eql(CouchRest::Model::CastedArray)
     end
 
     it "should raise and error if value is array when type is not" do
diff --git a/spec/fixtures/more/card.rb b/spec/fixtures/more/card.rb
index 7080ce9..7494b44 100644
--- a/spec/fixtures/more/card.rb
+++ b/spec/fixtures/more/card.rb
@@ -7,10 +7,10 @@ class Card < CouchRest::Model::Base
   property :last_name,        :alias     => :family_name
   property :read_only_value,  :read_only => true
   property :cast_alias,       Person,  :alias  => :calias
+  property :fg_color,         :default   => '#000'
 
-  
   timestamps!
-  
+
   # Validation
   validates_presence_of :first_name