lists cause unnecessary rerenders

Still debugging this, but I have this code:

var Firebase = require('ember-firebase');
var base = "https://pollster.firebaseio.com";

module.exports = Firebase.Hash.extend({

  countRef: function() {
    return new Firebase(this.get('ref').toString()+'/count');
  }.property(),

  incrementCount: function() {
    this.get('countRef').transaction(function(currentValue) {
      return currentValue + 1;
    });
  }
});

{{#each choice in choices}}
  ...
{{/each}}

Every time I call increment count on a choice the whole list gets redrawn. This is particularly problematic when I I'm trying to store these views to make some comparisons. Think of a multiple choice quiz component, you want to store the currently selected answer component, but every interaction with firebase causes everything to redrew so you can't keep state.

Sorry, I know this isn't actionable right now, but I will try to narrow it down some more later.

Start by reproducing the redraw with the {{#each choice in choices}} template and the incrementCount Firebase transaction shown in the issue. Trace which Firebase update causes the list to redraw and determine whether unrelated choice views lose their state. Done means the cause is identified and the list no longer redraws unnecessarily when incrementing a choice.