turns out there was no performance problems with the path (made a dumb mistake with implementation). However, during the analysis, I ended up adding event detection throttling which is pretty handy. It cuts down unecessary mousemove event handling dramatically and greatly improves performance when you have thousands of shapes

src/Stage.js

@@ -14,10 +14,12 @@
 Kinetic.Stage = function(config) {
     this.setDefaultAttrs({
         width: 400,
-        height: 200
+        height: 200,
+        throttle: 80
     });
 
     this.nodeType = 'Stage';
+    this.lastEventTime = 0;
 
     /*
      * if container is a string, assume it's an id for
@@ -549,11 +551,26 @@ Kinetic.Stage.prototype = {
 
         return false;
     },
+    _handleStageEvent: function(evt) {
+        var throttle = this.attrs.throttle;
+        var date = new Date();
+        var time = date.getTime();
+        var timeDiff = time - this.lastEventTime;
+        var tt = 1000 / throttle;
+
+        if(timeDiff >= tt) {
+            this._handleStageEventContinue(evt);
+        }
+    },
     /**
      * handle incoming event
      * @param {Event} evt
      */
-    _handleStageEvent: function(evt) {
+    _handleStageEventContinue: function(evt) {
+        var date = new Date();
+        var time = date.getTime();
+        this.lastEventTime = time;
+
         var go = Kinetic.GlobalObject;
         if(!evt) {
             evt = window.event;
@@ -623,10 +640,11 @@ Kinetic.Stage.prototype = {
             that._handleStageEvent(evt);
             that.clickStart = false;
         }, false);
-
-        this.content.addEventListener('mouseover', function(evt) {
-            that._handleStageEvent(evt);
-        }, false);
+        /*
+         this.content.addEventListener('mouseover', function(evt) {
+         that._handleStageEvent(evt);
+         }, false);
+         */
 
         this.content.addEventListener('mouseout', function(evt) {
             // if there's a current target shape, run mouseout handlers
@@ -641,14 +659,14 @@ Kinetic.Stage.prototype = {
         this.content.addEventListener('touchstart', function(evt) {
             evt.preventDefault();
             that.touchStart = true;
-            
+
             /*
              * init stage drag and drop
              */
             if(that.attrs.draggable) {
                 that._initDrag();
             }
-            
+
             that._handleStageEvent(evt);
         }, false);
 

src/shapes/Path.js

@@ -23,24 +23,20 @@ Kinetic.Path = function(config) {
             var c = ca[n].command;
             var p = ca[n].points;
             switch(c) {
-                case 'M':
-                    context.moveTo(p[0], p[1]);
-                    break;
                 case 'L':
                     context.lineTo(p[0], p[1]);
                     break;
+                case 'M':
+                    context.moveTo(p[0], p[1]);
+                    break;
                 case 'z':
+                context.closePath();
                     break;
             }
         }
-        context.closePath();
-        //this.fill();
         
-        context.fillStyle = '#999';
-        context.fill();
-        context.strokeStyle = '#555';
-        context.stroke();
-        //this.stroke();
+        this.fill();
+        this.stroke();
     };
     // call super constructor
     Kinetic.Shape.apply(this, [config]);