To me, a Wii U's only worth the new Smash Bros. game. Even though it'll also come to the 3DS, it's safe to assume that the Wii U version's gonna have far more than the 3DS one.
Black was hard for me, since my team was just random favorites not really suitable for battling (Emboar, Zoroark, Carracosta, Eelektross, Chandelure [yes, 2 Fire-types, lemme alone], and Beheeyem). My White team looks far more impressive, though (Samurott, Shiny Ninetales, Hydreigon, Lilligant, Crustle, and Archeops). I hope Gray has more things in it to slow you down. It's the travel that becomes the fun part.