I'm using draft.js in production (at http://www.guilded.gg). I just started looking for a replacement for a few reasons:
1. Draft is pretty broken on Android, despite being marketed as a cross-platform project. The team says that they're not working on fixing it, and it's not trivial to fix. This is a dealbreaker on its own.
2. I've had users encounter bugs where the Draft editor will serialize state that it can't read - so you can save something, and then cannot reload it. It appears to happen when doing some weird combination of adding and deleting block elements. This is a dangerous and frustrating bug.
3. In my opinion, the DraftJS API is difficult to use and extend.
Do you (@author) plan to support Android and iOS? If so, I'll definitely give this a shot.