It's not going to be more powerful then the Wii U in raw power, and it's not even going to be close to the XBO. Best case scenario is it's in line with the Wii U in raw power.
You're sipping some serious cool aid if you think a mobile chip poised for a $250 launch is going to "run miles" around the Wii U or be in line with the XBO. On paper it can, but mobile chips don't actually run anywhere near their on paper specs suggest.