While cosmetics might seem minor, these costumes are fully animated and detailed, adding a layer of whimsy absent in the "gritty" PS3/360 versions. For fans of crossover content, this alone makes the Wii U ISO the better preservation target.
A clean Tekken Tag Tournament 2 Wii U ISO is approximately . However, tools like Wii U USB Helper or CDecrypt can convert it to a loadiine-ready format (roughly 6GB), making it smaller than the PS3 version’s 15GB install. For archivists, smaller is better.