I for one have dumped countless hours into getting semi-competitive at MvC3 and UMvC3. While I'm far from winning EVO, I feel like I'm good enough to have a good match with an average player, but I dont think i have the patience to get that good at it.
That said, its probably one of my favorite fighting games out. The fan service from both Marvel and Capcom is great, and its really fun overall. The cast is balanced alright in my opinion, though there is a pretty clear margin between the best and worst characters in the game. Its no MvC3 though (MSS anyone?) but still I enjoy it a lot.
And yeah, as Jesse said, Arcade Stick is the way to play IMO. I've played against great pad players, but I think Arcade Stick is the way to go. Its hard to master, but its worth the time I feel.