Well, in the PS2 version you can unlock Gill for use which leads to absolute cheapness battles. The timing on the parry system is a bit off as well, due to a lower frame rate on the PS2 in comparison.
To see a good example for those with DC and PS2 versions, use Ryu's Shin Shoryuken.
The main thing that I like in this game is that it has the best cancel useage and near perfect parry system. I love canceling, especially from a Fierce Shoryuken in a Shippu Jinrai Kyaku. Really adds up the damage if you time it just right. It would be perfect if it had the KOF style dodge roll and grabs with fierce like Alpha 3. Ken would be that much more unstoppable with his kick from CvS2 that Sean uses. This game also boast my favorite super system.
Who do I use?:
Ken: My #1 guy, call me a shoto if you want, Ken rules in this game. So many combos to use, with a great super that fills insanely fast. I absolutely abhor Chun Li.
Yang: A close second, Yang's speed is great and he can pressure like few others. I tend to use the roll kick super, but I'll occassionally use his split into 3 technique, for maximum damage in minimum time. Only fault I find with Yang is that his teleport is not very useful. Never, ever, fight a good Ken with him though.
Remy: IMO the best charger ever (well tied with Ash). High and low sonic booms are enough to throw others off, has a great flash kick that is fast with good forward and upward movement that can quickly block on landing, plus a non-charging move to keep people off you. He's the guy I bring to make Ryu-sers crumble. Super choice: Supreme Rising Rage Flash, of course.
Gill: Only if I don't feel like paying any attention to the match. Seraphic Wing means I'll never even see Resurrection.
Ibuki: I'm not great with her, but I enjoy using her. Her moves are quite awesome, especially the EX dash neck break. Tricky to use, but also tricky to fight. I tend to go with Yami Shigure, just because it looks cool and most of my friends rarely go aerial.
Why wasn't Cammy in this game? She would have been awesome, Cannon Spike cancelled into Killer Bee Assault, anyone?
Some of the story in it confuses me though.