I can for the life of me not beat any Ryus (and some other characters) that just move around like crazy. Dashing back, forward, neutral jumping, jumping in with lk, using moves that cover some space, that sort of stuff.
I try to outfootsie them and yeah, I get my single hits in but one big jump-in or good knockdown from them and I eat four times the damage.
Sometimes I wish I could just see a top player with my character against my current opponent to get an idea of what I should do. This is the first real wall I've hit in this game.