After learning that Wii remote controls are only available for co-op, I'm honestly thinking I should just get the Wii version and play it upscalled on Wii U. Hate to say it, but the Wii U version seems to be one of the examples of a rushed port job. Remember Junction Point themselves said the Wii version was the lead version of the game, and I think Blitz had plenty of time to make the HD versions of the game for 360 and PS3, while I get the feeling Heavy Iron didn't get as much time to do that (the Wii U version was sorta confirmed almost out of nowhere in September during Nintendo's Wii U conference).
It's like I've said many times over though, launch titles are never the best indication of a system's power (especially in the case of ports most of the time, since devs might not be 100% in tune with porting all the code and such to the new hardware just yet). Compare a game like FEAR 1 to FEAR 2, or Quake 4 to Halo 3, and you'll see that it's usually only about a year or two later you really start to see how much better devs get with the hardware.