I'm still choosing react, even after the patent clause. Facebook even wrote a blog post about it:
code.facebook.com/posts/112130496157735/explainin…
Obviously, their position is biased, so take that in consideration when reading that post, but I believe their intentions in this case are sincere.
The following paragraph summarizes pretty much what the patent is for:
The patent grant says that if you're going to use the software we've released under it, you lose the patent license from us if you sue us for patent infringement. We believe that if this license were widely adopted, it could actually reduce meritless litigation for all adopters, and we want to work with others to explore this possibility.