Dark Sonic
Smash Hero
....no he's not dude. All of the high level melee players agree that both Fox and Sheik are better characters than Marth <_<. Even FALCO is debatable.to a character that's arguably best or second best in the game.
Just be careful with prematurely nerfing him, since he does have clear defined weaknesses in melee (very vulnerable from below, bad under shield pressure, trouble getting up from the ledge safely, trouble working in confined spaces, ect.). It's quite possible that some brawl characters will be able to abuse these things better than melee characters after they're meleefied.
I'd stick to smaller nerfs like nerfing damage before going into things like reducing his kill power (which is actually not that good outside of tippers, which he CAN'T combo into past 80% or so)