Thanks for mentioning Ractive (http://www.ractivejs.org/), first time I've seen it.

I'm wondering why you would prefer angular for a form-centric app?

I've used angular and rivets.js + backbone with success, my preference being angular but Ractive looks like a way to get awesome templating and databinding without committing the entire app to a single monolithic framework.

It also seems that server side rendering is more reachable with it's mustachy roots.