Browse the AngularJS source code and you'll see it littered with jsperf, they care about performance and you'll learn a lot about javascript performance.
You'll write fewer files in AngularJS since you don't need to create a file for every view and model. I'd say I write 60% less javascript.
Testing is easy, AngularJS integrates easily with Testacular, and because you never manipulate the dom directly, all your code you write is logical making writing test code straight forward.
You won't see many tutorials but when you google for specific problems you'll find many jsfiddle examples which made learning AngularJS easier than BackboneJs and EmberJS.