Slight advantage in performance. On that note, PC MASTER RACE!
Depends on which exclusive games you want to play..
Out of the two, Xbox. Wii U is the best though.
Nothing on PS4 sounds of much interest to me, except No Man's Sky. So Xbox wins, because I've played a few good games on it, it has better controllers, and better multiplayer. (Not sure about the multiplayer, that's just some comments I've heard about PS4 multiplayer being inferior to Xbox one. I'd certainly buy a Wii U before PS4.