My guess is that it's still not as good as SF2, which, IMO, continues to be the best competitive, most balanced fighting game of all time.
It's actually a lot of things on the fundamental side of the equation. For example, inputs are VERY lenient, which makes it much more mash-friendly, but also makes it so that it's easier to muddle or outright fudge commands (especially depending on which controller/arcade stick you use). And in any good fighting game, one should want something that will remove anything closer to "randomness" in your overall execution.
Then there's just other things relating to how the games feel so...."boring", compared to other choice games in the saga. It doesn't have Turbo or Super Turbo's pure finesse, Alpha 2 or Alpha 3's robust game engines or 3S's technical depth. The end result is just overly homogenized product that does more to stay "safe" within the bounds of SF2, without having some of the charm that made Turbo or Super Turbo as fun as they were.
Hopefully MvC3 takes some of the balance that TvC has. I.E. you can actually win with every character and there is no pre-dominant team of God Teams in competitive play.
Karas and Zero say "what's good, [shadow runner] WHAT'S REALLY GOOD?!?".
In a game where the rush-down rules, Karas and Zero are clear and away the cream of the crop. Y'know there's some BS-involved when some one who knows what they're doing with the "Wii-mote only" option can STILL CLEAN HOUSE with these two.