i've been using ember for the past three months in a fairly complex project and i'm very happy with it ; a platform that builds business web apps dynamically for devices (20+ pages,250+ fields per app with validations, calculated fields, conditional flows etc , rendering/theming in jqm -> packaged with phonegap) and client web browsers (render/theme in bootstrap),the backend is in java. So, i certainly don't feel the same way for emberjs as the writer.

I had decided to build the frontend in a js mvc framework and the candidates were backbone, emberjs (pre version), angularjs. Read about them and gave backbone a try, however from the documentation only emberjs approach felt better maybe because of a similar in-house development java framework that we work on. So i tried to give emberjs a try at the same time, due to the tight deadlines. I dropped backbone, and spent more time on emberjs because everything simply worked and fitted together nicely. All these binding mechanisms are great and actually work :) . Haven't tried angularjs.

The system now works with emberjs (pre and rc) with a nice layered architecture and separate independent business logic modules.

My advice is to read the documentation carefully and choose what fits better to your needs and coding styles.