The western versions have always been development versions sold as if they were the final build. CE and HF western versions are basically incomplete versions of the game. And S2 versions had a major glitch in Zangief's kick 360. It's really sad, but that's how it was. And they were still the best arcade games, hands down.
As for bottom tier characters: Rog was bottom tier in the western versions, while Chun was bottom tier in the Japanese version of Dash/CE. Chun is bad due to having no invulnerable anti-airs and a pretty short range on her crouching kicks. Rog happens to be worse in the western versions because his TAPs never charge up.
There's lots of stupid, non-SF stuff in SF4. You need to be in denial not to see that, or simply not know how it used to be played. Stupid anti-airs, the jab nonsense, weird hitboxes, the COMPLETELY DIFFERENT start-up, active and recovery times, the floaty jumps. The opinions one sees in this thread is why almost every thread 09ers touch gets pointless and would better be deleted.
In Super SF2, Ken's tatsu didn't knock down. Ryu's did. It's been like this up until now.
JJust for the sake of curiosity, here are some differences up until SSF2, since in ST they are very different:
Ryu has a few frames, while stunned, when he eats double damage.
Ryu's kick throws do not move himself (and the enemy) as far as Ken's, since he doesn't roll.
Ken's tatsumaki combos and move faster.
Ryu's tatsumaki have invulnerable start-up and recovery, and knock down.
Ryu's hadoukens have faster start-up.
Ken's shoryukens have faster start-up and recovery.
Ken's shoryukens have a bigger hitbox.
Ken's diagonal jumping fierce punch has better priority (smaller vulnerable area below).
Ken's neutral jumping fierce punch has worse priority (bigger vulnerable area below).
IIRC, the same differences from CE.
Same differences from CE, plus:
Ryu's hadoukens have a different animation art.
The recovery and the hitbox on Ryu's hadoukens increase as the strength of the punch increases. (So there an advantage and a disadvantage.)
Ryu gains a new special move: the shakunetsu hadouken.
Ryu's tatsumaki still have some invulnerability, but only during start-up, and it's reduced to 4 frames.
Ryu can not combo a jumping attack into and air tatsumaki against most enemies (first attack whiffs, only the second one may combo).
Ken's fierce hadouken sets the enemy on fire and hits up to three times.