I'd counter that for every person who says he loves Superman, there's a guy who complains that Superman is overpowered. If you were writing this book only to satisfy current Superman readers, I can see why this would be a lousy idea, but if your goal were to entice people that might be on the fence, this could be a decent idea. Mind you, I don't subscribe to the claim that Superman is overpowered and therefore uninteresting, but I think this kind of tinkering might be okay.