We recently had to make a choice between frameworks and my colleague and I came from a jquery/rails background, virtually no practical experience with js frameworks. We started with backbone.js, but I was immediately frustrated. We then switched to angular.js after going through the tutorial ~2hrs.

Four months and a lot of learning later, I am very happy with our choice. If I ever get some spare time I want to write some posts on angular from a rails perspective. I found the rails nomenclature I was used to didn't directly translate to angular.

One other reason we chose angular, it is backed by Google. The meetups I have attended in Seattle keep growing steadily and the mailing list is great.