The article above by Jesus Rodriguez is a good article. It shows how Angular is easy to create _very_ small widgets with. But it doesn't tell you much about how to write a big application.
My experience with Ember (we're creating a very large app with around 100 different routes) is extremely good. More functionality != more bulk. All new features we add to the app fit nicely with the existing code. We never have to go back and refactor large parts of the app. It's the same simple pattern you apply over and over again. I seem to get the opposite impression from Angular apps, where as soon as your app grows more complex you need to take a lot of things in a different direction.
Take a look for yourself at some big and serious companies who are building large open source Ember apps:
Discourse: https://github.com/discourse/discourse/tree/master/app/asset...
Travis CI: https://github.com/travis-ci/travis-web/tree/master/assets/s...
Balanced Payments Dashboard: https://github.com/balanced/balanced-dashboard/tree/master/a...
And check out the new getting started guides: http://emberjs.com/guides/ (especially the screencast by Tom Dale)