Superman would not be buff!
Think about it. How does Superman get the kind of exercise that will make his muscles grow? The heaviest weight on the planet is like picking up a piece of paper to him! Does he work out by picking up Mt. Everest? Not if he wants to stay in hiding. There's simply no way for him to have a regular workout that would provide enough exertion to build that kind of muscle mass.
He would look more like someone who's living in space or on the moon. Either be morbidly obese or skinny and emaciated. Given that reality, who should really be playing Superman?
I'm thinking Michael Cera. He already has disguise glasses.
