I plead the 5th when it comes to knowledge about game systems, but DH tells me that the XBox One gets terrible reviews.
Well, XBox one has itss issues, it got some bad press to start with, Microsoft didn't take the gamer's love of buying used games in to consideration...and there is something about the graphics not being as high as the PS4...
...but that said, the WiiU gets worse reviews due to even worse graphics and a lack of games.
I had a Wii, loved it at first, thought I was better than the Xbox 360 and PS3 people...but as more an more games passed the Wii by because of the weak processor and graphics, I finally switched to a 360...think my next one will be a PS4.
A key indicator was the Disney Infinity system...they made 1.0 for all systems, but the Wii had elements of the game removed due to the weak system...the 2.0 game isn't available for Wii, but is for 360 and PS3...while the WiiU is better than the Wii, it is not on par with the PS4 and XBoxOne in terms of processing power, it is a "generation" behind. There is a reason the price keeps dropping, they are trying to save the system.
I would personally warn anyone against the WiiU...it is flailing, trying to pull in other games, and not succeeding. I think buying one now is only for the people that must have the newer Mario games...that is the one series you can't play on other systems...and I've enjoyed the XBox Kinect more than the Wii controls for motion sensitive gaming.
That is my take on it, your mileage my vary.