Angular or Backbone: what are startups using?

The best thing about Ember that I always tell curious newcomers is that Ember is both easy to make small apps with, but it's also trivial to keep expanding into really big apps. You can keep repeating the same pattern infinitely without rewriting old parts of the app, and without feeling like adding bulk to the app. I see our app as a large very flat structure. We can go in and replace every small piece in isolation to everything else.

My impression of something like Angular.js is that often when you want to add new features you have to go back and refactor a lot of stuff (just check out the cage match between Tom Dale and Rob Connery https://vimeo.com/68215606). It feels like a pyramid that will need a lot of maintenance to stay standing.

This is not the case with Ember. Ember was written by some very smart people, who have spent _a lot_ of time refining how an app should be developed in the long run. Features are prepared for the future. Both the future of browsers and JavaScript but also the future of developers' apps.

I am sure that Ember will prevail over all the other frameworks within the next year and stay on top for many years to come.

You may have been able to pick apart angular-ui to include only their datepicker directive.

Mixing jQuery and Angular just seems like a bad idea, to me...

There are domains (like web apps) that really suit Angular, and rendering on the server simply isn't an option. There are content sites which should be handled on the server. Then there's the all the stuff in between. Admin for a CMS? You could go either way on that so you need to weigh it up yourself. These days I'd swing for Angular in that case because by the time you've loaded a single grid directive you have 50% of the system running.

The performance overhead swings both ways - it's not great to be dragging truckloads of html over the network to a mobile device either. Of course you need to test for your specific use case. I definitely get your point, and if you're building for mobile you'd want to do proper testing before banking on Angular.

One thing I would say is that I use Angular for my web app which deals with huge (million node) svg documents and performance-wise it actually deals with it really well (once you've optimised the bottlenecks into directives). From a code sanity point of view it's a life-saver.