Seems pretty good, but its pretty early in the game and I'm basing all of what I know off of online play + watching two tournaments, heh.
IMO, the only things I find wrong with the game are the following:
-Nightmare's damage output when compared to his rate of mobility (too much damage)
-Natsu's damage output compared to her rate of mobility (too much damage)
That's pretty much it. Mitsurugi is obvious; he's always been pretty hard to deal with in every SC game, IMO. He's still pretty much mid-high.
Apparently, I'm not the only one who thinks that those characters are unbalanced on 8WayRun.
Oh, and Just Guard > Guard Impact.