I'm betting on React, big time!
It's very simple to reason about big applications in React, because of it's rendering paradigm and component hierarchy. That's something I was never able to do before in javascript, even on angular (just tested the version 1).
On top of that, it's very fast, has awesome documentation, ever growing community and the library just gives some freaking good error messages and warnings when you mess things up :')
But, don't have my word for it. Test it yourself! You could get the basics of react in a single day.
If you have just 2 alternatives in mind, there's no reason to spend months learning something before testing them to see what fits you best. Take like 2 days for each technology and play with both before commiting. That's my advice to you (: