Depends on which version of 'Rog you're looking for.
Champion Edition
Practically not worth it. Charge time on 3button punch is waaaayyy too long, no other fireball defense to speak of. Anti-air priority isn't there, and all of the boss characters are a bit rushed and one-dimensional, especially 'Rog. If your 'Rog is a killah on Champion, then you are fucking awesome at SF.
Hyper
First hint that 'Rog would become a killah. Suffers from many of the same shortcomings that Champion 'Rog did, but he deals greater damage and 3button punch was improved. Extra frames of invincibility added to it, but many of his punches still only hit high.
Crossing up with 'Rog in Hyper is fucking sweet though. This is where all of his walk-under mixups after grab/headbutt originated. Tickthrowing with 'Rog in Hyper truely is "killah". Unfortunately it's still pretty hard to pressure with him here.
Super Turbo
Uh-oh, puncher heaven!
Birth of the rushdown 'Rog. So many ways to get in close and punish traps. Once inside 'Rog could eat up a lifebar like it was not even there.
Standing strong became a sweet AA, as did crouching Fierce.
Pressure opponents by mixing jabs and crouching forwards. Stand fierce if pushed back too far. Dash uppercut gets you back in close since most people continue to block. Once in close grab/headbutt into mixups. Walk under low jab reset after grab, or walk under low forward deep into grab, repeat. Feign crossup into straight grab again, or reset pressure. Jump fierce serves as an overhead and is a nice little trick, it also deals hella damage. 'Rog meters up quick in ST, so all the grabs and hits off of mixups give you meter fast.
In ST 'Rog eats up shotos and Blanka like a motherfucker. Tough matchups for me personally are Sagat, Guile, and Honda.
I don't know what else to say really, until you've played a killer 'Rog, or have one yourself, it's unfathomable to imagine just how strong he is in ST. Easily one of the best characters in the game.
Zero/Alpha 3
I don't play the Alpha series, but from what I've seen in arcades he can be used to quite an ass-kicking degree. Apoc in Las Vegas has a murderous 'Rog in Alpha 3. V-ism I believe?
CvS2
Not what he used to be. I've seen a few people use him in comp, but I don't personally. I haven't played him enough in CvS2 to really realize what he is capable of. Seems to me that his rushdown ability isn't really there, feel free to correct me if I'm wrong.
EDIT: This thread is proof that either
A) No one comes to the Gameplay section of the forums anymore
or
B) All those people who voted for 'Rog in the claw v. boxer poll are just dumb-ass blind followers and don't actually know shit about SF b/c they haven't even bothered to post here yet.