diff --git a/PRIMER.md b/PRIMER.md
index 2508799a..11b77286 100644
--- a/PRIMER.md
+++ b/PRIMER.md
@@ -167,8 +167,8 @@ MyElement = Polymer({
   is: 'my-element',
 
   factoryImpl: function(foo, bar) {
-    el.foo = foo;
-    el.configureWithBar(bar);
+    this.foo = foo;
+    this.configureWithBar(bar);
   },
 
   configureWithBar: function(bar) {
diff --git a/src/lib/polymer-bootstrap.html b/src/lib/polymer-bootstrap.html
index cdfc63a4..b21677b3 100644
--- a/src/lib/polymer-bootstrap.html
+++ b/src/lib/polymer-bootstrap.html
@@ -60,8 +60,6 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
       return prototype.constructor;
     };
 
-    window.Polymer = Polymer;
-
     if (userPolymer) {
       for (var i in userPolymer) {
         Polymer[i] = userPolymer[i];
@@ -98,4 +96,3 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
   };
 
 </script>
-
diff --git a/src/lib/style-transformer.html b/src/lib/style-transformer.html
index 1a072f76..419c38d6 100644
--- a/src/lib/style-transformer.html
+++ b/src/lib/style-transformer.html
@@ -30,9 +30,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 
      * :host(...) -> scopeName...
 
-     * ::content -> ' ' NOTE: requires use of scoping selector and selectors
-       cannot otherwise be scoped:
-       e.g. :host ::content > .bar -> x-foo > .bar
+     * ::content -> ' '
 
      * ::shadow, /deep/: processed similar to ::content
 
@@ -161,6 +159,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
         var stop = false;
         var hostContext = false;
         var self = this;
+        selector = selector.replace(CONTENT_START, HOST + ' $1');
         selector = selector.replace(SIMPLE_SELECTOR_SEP, function(m, c, s) {
           if (!stop) {
             var info = self._transformCompoundSelector(s, c, scope, hostScope);
@@ -256,7 +255,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
     // NOTE: this supports 1 nested () pair for things like
     // :host(:not([selected]), more general support requires
     // parsing which seems like overkill
-    var HOST_PAREN = /(\:host)(?:\(((?:\([^)(]*\)|[^)(]*)+?)\))/g;
+    var HOST_PAREN = /(:host)(?:\(((?:\([^)(]*\)|[^)(]*)+?)\))/g;
     var HOST_CONTEXT = ':host-context';
     var HOST_CONTEXT_PAREN = /(.*)(?::host-context)(?:\(((?:\([^)(]*\)|[^)(]*)+?)\))(.*)/;
     var CONTENT = '::content';
@@ -266,6 +265,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
     var CSS_ATTR_SUFFIX = ']';
     var PSEUDO_PREFIX = ':';
     var CLASS = 'class';
+    var CONTENT_START = new RegExp('^(' + CONTENT + ')');
 
     // exports
     return api;
diff --git a/src/standard/configure.html b/src/standard/configure.html
index d32205aa..8d4102a7 100644
--- a/src/standard/configure.html
+++ b/src/standard/configure.html
@@ -136,7 +136,9 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
             for (var i=0, l=fx.length, x; (i<l) && (x=fx[i]); i++) {
               // TODO(kschaaf): compound bindings (as well as computed effects)
               // are excluded from top-down configure for now; to be revisited
-              if (x.kind === 'annotation' && !x.isCompound) {
+              if (x.kind === 'annotation' &&
+                  x.effect.kind !== 'attribute' &&
+                  !x.isCompound) {
                 var node = this._nodes[x.effect.index];
                 // seeding configuration only
                 if (node._configValue) {
diff --git a/test/unit/attributes.html b/test/unit/attributes.html
index 76d4bd76..66e45fba 100644
--- a/test/unit/attributes.html
+++ b/test/unit/attributes.html
@@ -283,7 +283,11 @@ suite('hostAttributes', function() {
     // applied to property with effect
     assert.strictEqual(compose.$.basic.prop, 'compose');
     assert.equal(compose.$.basic.propChangedCount, 1);
-    assert.equal(compose.$.basic.attr1ChangedCount, 1);
+    // Note: Attribute binding does not participate in efficient configuration
+    // per #3288.  As such, a property bound with an attribute binding will
+    // see its default value first, then be overwritten when the attribute
+    // binding runs and re-deserializes to the property, hence 2 observer calls
+    assert.equal(compose.$.basic.attr1ChangedCount, 2);
     assert.equal(compose.prop2, 'hi');
   });
 
diff --git a/test/unit/configure-elements.html b/test/unit/configure-elements.html
index da91f857..c3eee344 100644
--- a/test/unit/configure-elements.html
+++ b/test/unit/configure-elements.html
@@ -128,7 +128,7 @@
 
 <dom-module id="x-configure-host">
   <template>
-    <x-configure-child id="child" content="{{content}}" object="{{object.goo}}"></x-configure-child>
+    <x-configure-child id="child" content="{{content}}" object="{{object.goo}}" attr$="{{attrValue}}"></x-configure-child>
   </template>
   <script>
     Polymer({
@@ -156,6 +156,9 @@
         },
         stomp: {
           value: 5
+        },
+        attrValue: {
+          value: 'attrValue'
         }
       }
 
diff --git a/test/unit/configure.html b/test/unit/configure.html
index 5c295b7d..40381e83 100644
--- a/test/unit/configure.html
+++ b/test/unit/configure.html
@@ -22,9 +22,9 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 
   <x-configure-value content="attr" object='{"foo": "obj-attr"}'></x-configure-value>
 
-  <x-configure-host></x-configure-host>  
+  <x-configure-host></x-configure-host>
 
-  <x-configure-host content="attr"></x-configure-host>  
+  <x-configure-host content="attr"></x-configure-host>
 
 <script>
 
@@ -53,7 +53,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 
     test('value set in properties initializes correctly', function() {
       var e = document.querySelector('x-configure-value');
-      testConfigure(e, 'default', 'obj-default');      
+      testConfigure(e, 'default', 'obj-default');
     });
 
     test('attribute overrides value set in properties', function() {
@@ -81,6 +81,12 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
       assert.equal(e.readOnly, 'default');
     });
 
+    test('properties for attribute bindings not configured', function() {
+      var e = document.querySelector('x-configure-host');
+      assert.equal(e.$.child.getAttribute('attr'), 'attrValue');
+      assert.equal(e.$.child.attr, undefined);
+    });
+
   });
 
 </script>
diff --git a/test/unit/polymer-dom-elements.html b/test/unit/polymer-dom-elements.html
index d4afa8b2..53956048 100644
--- a/test/unit/polymer-dom-elements.html
+++ b/test/unit/polymer-dom-elements.html
@@ -200,7 +200,7 @@
       box-sizing: border-box;
     }
 
-    :host ::content .add3 {
+    ::content .add3 {
       box-sizing: border-box;
       height: 20px;
       background: #333;
@@ -240,7 +240,7 @@
       padding: 4px;
     }
 
-    :host ::content .add2 {
+    ::content .add2 {
       box-sizing: border-box;
       height: 20px;
       background: gray;
@@ -281,7 +281,7 @@
       padding: 4px;
     }
 
-    :host ::content .add1 {
+    ::content .add1 {
       box-sizing: border-box;
       height: 20px;
       background: lightgray;