Wii U and 3DS combined most assuredly ARE less powerful than PS3/Vita. I figured that was sort of a given. 3DS is significantly less powerful than Vita, and if Wii U is just on par with PS3, then this is no surprise.
Not that power matters, anyway. Xenoblade is one of the best games of the last couple years, and it's running on GameCube 1.5, so this whole debate is pointless.







