Getting Started with Ember Data

I think Ember and Ember Data are extremely interesting, but there are definitely some caveats to using Ember/ED over other MV* JS frameworks or rolling your own persistence layer.

I think this post does a good job of mentioning them, but I would also mention that a huge caveat I came across in a personal project (after I developed my API, of course) was that ED and Ember.Route don't support nested resources in APIs they consume. This means that you can't use conventions like /users/1/posts in your API, you have to use shallow resources (i.e., /posts?user=1). This is definitely a trivial detail if you haven't yet designed your API, but is kind of a pain in the ass if you don't know that going in and design your API with nested resources first (as I did).

Is Ember Data considered stable yet? Last I'd heard it was in a beta state but was starting to be used in some production environments.