USD600-700 for only an average 20-30% faster GPU? I would say, that is not a good upgrade, unless you can sell and get a good price for your current Titan X.
I tend to say no, if money is no object, then perhaps. I guess the other question is what res do you play at and would a stronger GPU make your play more enjoyable? And if absolute max frames are what you want wait on the Titan or 1080ti of this generation of you'll just be mad again when they come out
USD600-700 for only an average 20-30% faster GPU? I would say, that is not a good upgrade, unless you can sell and get a good price for your current Titan X.