the documentation has improved rather drastically as of late. the router api is stable going forward, so it's actually a pretty good time to be experimenting with ember (though this was not true about 4 months ago).

Personally, I really like ember. I think most people would have a better experience with ember if:

(1) they avoided learning off of the master branch during the crazy api changes over the last few months

(2) avoided ember data for the time being (or ever, I have my doubts about how viable it is)

(3) they asked questions on stack. the ember core team is actually pretty snappy at answering questions.

but there is still a bit of lingering weirdness with the router that people should look out for, the things that come to mind are:

a) back button errors

b) awkwardness in the serialize/model hooks depending on whether you're navigating through the app, or trying to get to a url in a new browser window

but despite its shortcomings, I've really grown to love the organization that ember gives to my javascript code base, and how it would make my program scale as it grew in size and complexity.