Not to cut you off but I wouldn’t say React is complete framework as Angular or Emberjs. React could be thought about as the View component of MVC. And I would say the only people who may struggle grasping react would be designers who work with HTML and CSS in separate files(Separation of concerns).
For backend developers that use JS(and know JS very well) jumping into react shouldn’t take you long(even though it can go into your head and may cause lots of confusion).
In my own conclusion, one can go ahead and pick any framework he or she likes.(even though i would also say trying react won’t be bad).
If you choose react you have to start thinking of your web app as component. I ranted when react said this, because it looked like i was doing that already. But with react working with teams becomes so easy.(When doing TDD) Because everyone can go into their caves and build components and when we sit we just get to fix everything together like LEGOs.
OMG. I think this comment can pass as a separate post. But react is an awesome library to learn for anyone. Things that I think may be confusing are rather states(with flux, redux) and props(not soo confusing)