I'm watching Hsien Chang right now, and you guys are right, he's probably the best Dudley right now. He doesn't have Marn's rection time, but since he plays Dudley correctly, it's not necessary unless he was going to fight a Dhalsim or something like that.
Hsien Chang plays pretty similarly to how I play Dudley, which is reassuring. I never tried to option select EX Jet Uppercut, though, which I thought was pretty interesting. He has better execution on his pressure strings than I do, which is something I'm always trying to work on. He still uses more superfluous hit confirms than I do, but not as many as Marn.
Really solid Dudley.
edit:
just finished watching the Daigo-Hsien matches.
Hsien's last 3 fights were embarrassing as a Dudley player. How does he not know how to deal with cMKxxfireball? that's Ryu's #1 anti-Dudley tactic. After that, it just got sad. Dropping simple combos all over the place, fucking up the pressure, missing huge opportunities to anti-air with the super and escape the corner with ducking, it was bad.
He plays Dudley better than Marn, but he doesn't have the other skills to make him a better player.