So now I'm in a pickle (for a 2 GPU setup):
Titan X:
(+) Much better SLI support, especially day one
(+) GPU-PhysX (yes, few games, but I like it and I play Batman and Witcher)
(+) Much better performance in CPU bottleneck. Might be critical for GTA 5 (open world)
(+) Gameworks (I don't like...