Both the wired and wireless have the A and B buttons at a rediculous angle.  In my opinion, they should either be straight, as on the the original NES pads, or angled to match the Y and B buttons of the SNES pads.
Their layout differs in that on the wired, Start and Select are over the A and B, with Turbo and Slow in the middle, with the wireless having Start and Select swapped with Turbo and Slow.  
One of the reviews I read mentioned the wired controller having extra A and B buttons on the shoulders, which is rather useless.  Had both A and B been included on the left side, one-handed play in RPGs would have been possible.  As I have a Famiclone that came with pads with an SNES-style layout, shoulder buttons included, it seems like they were simply following the formula, not really bringing anything new to the table.