Just a note about our experience with pre-1.0 releases (December-ish and previously) and the latest from master: Back in November and December I also noticed that I needed to close my tab every hour or so, since Chrome simply became slower and slower.
This issue is completely gone. I can have the same tab with our Ember.js app open for days, and I don't see any performance degradation.
I don't know if this is something that was fixed by Chrome or the Ember source code (or something we did terribly wrong at that time). But no matter what, it's gone, and I'm happy about that.
I wouldn't worry too much about a difference of 6MB in memory consumption. The important thing is that there are no memory leaks, so people can use your app for hours.
A nice thing to remember, is that you are responsible for calling
destroy() on all objects that you created. Ember.js will do the same internally for everything that was created behind the scenes.