Yea, I like the S-Logic, it does widen the soundstage a bit, but it probably isn't going to create enough of a 3D type sound for gaming. Not many closed headphones that are made for music are going to be good for that though. I'd say you should search the forums for other gaming friendly sets as I don't have knowledge of them.
I just recently purchased both to see which one I liked. I ended up keeping the 780s, better detail at every level. I listen to mostly hip hop and rock too...If you already have the M50s and are looking to upgrade I'd say go for something better than the 780s though, but that's just me. Maybe something like the D2000 if you have the budget?
I want to spend 250 dollars max.