diff --git a/src/instance/mdv.js b/src/instance/mdv.js
index ce804af..b4bf7a5 100644
--- a/src/instance/mdv.js
+++ b/src/instance/mdv.js
@@ -32,7 +32,7 @@
       template.bindingDelegate = this.syntax;
       return template.createInstance(this);
     },
-    bind: function(name, model, path) {
+    bind: function(name, observable) {
       // note: binding is a prepare signal. This allows us to be sure that any
       // property changes that occur as a result of binding will be observed.
       if (!this._elementPrepared) {
@@ -45,9 +45,9 @@
         // clean out the closets
         this.unbind(name);
         // use n-way Polymer binding
-        var observer = this.bindProperty(property, model, path);
+        var observer = this.bindProperty(property, observable);
         // stick path on observer so it's available via this.bindings
-        observer.path = path;
+        observer.path = observable.path_;
         // reflect bound property to attribute when binding
         // to ensure binding is not left on attribute if property
         // does not update due to not changing.
diff --git a/src/instance/properties.js b/src/instance/properties.js
index 90d0726..174a241 100644
--- a/src/instance/properties.js
+++ b/src/instance/properties.js
@@ -22,7 +22,7 @@
       var n$ = this._observeNames, pn$ = this._publishNames;
       if ((n$ && n$.length) || (pn$ && pn$.length)) {
         var self = this;
-        var o = this._propertyObserver = generateCompoundPathObserver(this);
+        var o = this._propertyObserver = new CompoundObserver();
         for (var i=0, l=n$.length, n; (i<l) && (n=n$[i]); i++) {
           o.addPath(this, n);
           // observer array properties
@@ -36,26 +36,24 @@
             o.addPath(this, n);
           }
         }
-        o.start();
+        o.open(this.notifyPropertyChanges, this);
       }
     },
-    notifyPropertyChanges: function(newValues, oldValues, changedBits, paths) {
-      var called = {};
-      for (var i=0, l=changedBits.length, name, method; i<l; i++) {
-        if (changedBits[i]) {
-          // note: paths is of form [object, path, object, path]
-          name = paths[2 * i + 1];
-          if (this.publish[name] !== undefined) {
-            this.reflectPropertyToAttribute(name);
-          }
-          method = this.observe[name];
-          if (method) {
-            this.observeArrayValue(name, newValues[i], oldValues[i]);
-            if (!called[method]) {
-              called[method] = true;
-              // observes the value if it is an array
-              this.invokeMethod(method, [oldValues[i], newValues[i], arguments]);
-            }
+    notifyPropertyChanges: function(newValues, oldValues, paths) {
+      var name, method, called = {};
+      for (var i in oldValues) {
+        // note: paths is of form [object, path, object, path]
+        name = paths[2 * i + 1];
+        if (this.publish[name] !== undefined) {
+          this.reflectPropertyToAttribute(name);
+        }
+        method = this.observe[name];
+        if (method) {
+          this.observeArrayValue(name, newValues[i], oldValues[i]);
+          if (!called[method]) {
+            called[method] = true;
+            // observes the value if it is an array
+            this.invokeMethod(method, [oldValues[i], newValues[i], arguments]);
           }
         }
       }
@@ -72,17 +70,17 @@
         // if the new value is an array, being observing it
         if (Array.isArray(value)) {
           log.observe && console.log('[%s] observeArrayValue: register observer [%s]', this.localName, name, value);
-          var self = this;
-          var observer = new ArrayObserver(value, function(value, old) {
-            self.invokeMethod(callbackName, [old]);
-          });
+          var observer = new ArrayObserver(value);
+          observer.open(function(value, old) {
+            this.invokeMethod(callbackName, [old]);
+          }, this);
           this.registerObserver(name + '__array', observer);
         }
       }
     },
-    bindProperty: function(property, model, path) {
+    bindProperty: function(property, observable) {
       // apply Polymer two-way reference binding
-      return bindProperties(this, property, model, path);
+      return bindProperties(this, property, observable);
     },
     unbindAllProperties: function() {
       if (this._propertyObserver) {
@@ -124,24 +122,18 @@
     }
   };
 
-  // compound path observer
-  function generateCompoundPathObserver(element) {
-    return new CompoundPathObserver(element.notifyPropertyChanges, element);
-  }
-
   // property binding
   // bind a property in A to a path in B by converting A[property] to a
   // getter/setter pair that accesses B[...path...]
-  function bindProperties(inA, inProperty, inB, inPath) {
+  function bindProperties(inA, inProperty, observable) {
     log.bind && console.log(LOG_BIND_PROPS, inB.localName || 'object', inPath, inA.localName, inProperty);
     // capture A's value if B's value is null or undefined,
     // otherwise use B's value
-    var path = Path.get(inPath);
-    var v = path.getValueFrom(inB);
+    var v = observable.getValue();
     if (v === null || v === undefined) {
-      path.setValueFrom(inB, inA[inProperty]);
+      observable.setValue(inA[inProperty]);
     }
-    return PathObserver.defineProperty(inA, inProperty, inB, inPath);
+    return Observer.defineProperty(inA, inProperty, observable);
   }
 
   // logging
diff --git a/test/js/bindProperties.js b/test/js/bindProperties.js
index 55ca7fb..8941619 100644
--- a/test/js/bindProperties.js
+++ b/test/js/bindProperties.js
@@ -10,16 +10,18 @@ suite('bindProperties', function() {
   test('bind properties getter', function() {
     var a = {};
     var b = {bar: 1};
-    Polymer.api.instance.properties.bindProperty.call(a, 'foo', b, 'bar');
+    var observable = new PathObserver(b, 'bar');
+    Polymer.api.instance.properties.bindProperty.call(a, 'foo', observable);
     assert.equal(a.foo, 1);
     b.bar = 5;
     assert.equal(a.foo, 5);
   });
-  
+
   test('bind properties setter', function() {
     var a = {};
     var b = {bar: 1};
-    Polymer.api.instance.properties.bindProperty.call(a, 'foo', b, 'bar');
+    var observable = new PathObserver(b, 'bar');
+    Polymer.api.instance.properties.bindProperty.call(a, 'foo', observable);
     assert.equal(b.bar, 1);
     a.foo = 5;
     assert.equal(b.bar, 5);
@@ -28,7 +30,8 @@ suite('bindProperties', function() {
   test('bind properties paths', function() {
     var a = {};
     var b = {bar: {zot: 2}};
-    Polymer.api.instance.properties.bindProperty.call(a, 'foo', b, 'bar.zot');
+    var observable = new PathObserver(b, 'bar.zot');
+    Polymer.api.instance.properties.bindProperty.call(a, 'foo', observable);
     assert.equal(a.foo, 2);
     b.bar.zot = 9;
     assert.equal(a.foo, 9);