Superman is a bastard (sorry for language). He’s just “super”. No substance, no real personlaity, and he can do just about anything with his powers. And his only weakness is kryptonite, which, as we all know, is the most common thing on Earth. I think metal should be his weakness, that would give him problems.
Anyway, as for DC vs. Marvel, it’s not like 360 vs PS3 or Mac vs PC. There’s not even any competiton here. Marvel >>>>>>>> DC. Besides the new Batman films, those are incredibleness x 10.