Interesting... you mind explaining the reason for switching? If it was missing functionality, I'm sure the team would appreciate pull requests. I'm often dismayed that angular is grabbing all the spotlight these days and not many new web apps use backbone in general or chaplin in particular.
There is a tradeoff between speed of development and degree of customizability when it comes to frameworks. With CloudTunes, I was going for a highly-customized and performant UI, and at some point it simply became easier to go back down by one layer of abstraction and build it just with Backbone instead.
