I'm a wii u owner but its likely watchdogs will be the worst version on wii u. Pointless even considering it. I know for this game the gamepad had a real chance to enhance it but ultimately if the main graphics chug along at a lower frame rate its not worth buying. It's likely based on the same or similar engine to both the wii u Assasin's Creed games which were done by the same developers as watchdogs wii u will be;
http://www.eurogamer.net/articles/digitalfoundry-assassins-creed-3-wii-u-face-off
http://www.eurogamer.net/articles/digitalfoundry-assassins-creed-4-next-gen-face-off
This is what the face off said about the wii u AC4 "it's hard to recommend the Wii U game at all, despite its image quality matching PS3 and Xbox 360.". If anything the second game performs worse than the first on wii u. AC4 is slightly more ambitious and struggles more with frame rate on 360 and PS3 and this effects the wii u even more. So a 20 to 40% drop in frame rate is far more significant as the frame rates are already low.
I applaud people's attempts to keep multiformat titles coming to wii u but this is a title that the wii u simply isn't capable of pulling off. If they start removing pedestrians or the skyline train or weather effects to keep the frame rate up it will destroy the immersion of the game. Better to push for wii u versions of games that could perform well on wii u. Does the wii u really need another title that highlights its low performance level.
This is the likely ranking of the various versions;
PS4
PC
(Wasn't sure which to put top there as often console games are more polished and convenient vs the higher performance level that only a small percentage of PC owners can benefit from)
Xbox One
Xbox 360
PS3
wii u
