Thanks for the question, James!
I don't use either personally :P I think they both have their individual usecases, and I've not found a reason to use either on my personal work apart from side projects just to test the technologies out. At work, we use Ember.js, which I really like for its CLI and convention over configuration approach when working on teams. Create-react-app also provides this sort of convention, though I sadly haven't had a chance to play with that one much yet.