This is a new list that will serve as a temp wiki for Ultra Street Fighter 2 until someone puts it up on the official SRK wiki. It's main purpose is to point out the differences between USF2 and Super Turbo. This list is drawn from the comments in the main USF2 thread here in FGD. I can't find anywhere else on the net seriously discussing this game. Please let me know if anything needs to be added and I will add it!
-Based on the JPN ST rom (unverified but very likely Capcom used the Dreamcast ST port as a base like Sirlin did for HDR). Gief's neutral headbutt auto-dizzies on hit in USF2, which only happens on the JPN versions of SF2.
-Runs at 1.35x speed of JPN Turbo 0. ST runs at 1.43x JPN Turbo 0. So 5.6% slower.
-It is speculated that different stages in ST run at different speeds (i.e. Gief and Honda stages are slower and Vega's stage is fast). This appears to be fixed now.
-Damage and stun are fixed instead of slightly variable like normal SF2.
-"Bugs" found in ST have been squashed. No moves are storable. Ken/Sagat/Dhalsim can do reversal supers. Moves that hit on the first frame (Blanka ball, Akuma air tatsu, Ken's HP SRK) are no longer 50/50 unblockable. Fireball characters are no longer able to get shorter recovery on MP and HP fireballs via kara cancel techniques.
-Throw teching is now a neutral no-damage clash like later SF games. Command grabs cannot be teched. Unknown yet if throwboxes were made the same length or if every character has a different one like normal SF2. Also unknown if you could tech a normal throw if someone attempts a grab outside of the target's throw range.
-Health bar no longer displays zero vitality while a character is alive. One pixel of health can ether equal one pixel of chip or zero life left making it impossible to differentiate between the two.
-Special move motions have more lenient timings (fixed input window like HDR) which makes certain moves easier/harder depending on what character you are using.
-Fireballs do a little more damage across the board.
-Akuma is unlocked, meant to be used competitively, and is slightly towned down from his ST incarnation. Has raging demon super.
-Evil Ryu and Violent Ken are included.
-Very slight "balance" changes have been made to certain characters.
-Other as-of-yet unexplained gameplay differences related to timing of moves.
Ryu: No change. Fixed input window might mess up walkup SRK or walkup fireball as it did in HDR. Changed input for his knockdown red fireball.
Ken: Super can now be used as a reversal. Certain moves have easier inputs.
Chun-li: Super cannot be stored, making her a weaker character than in ST.
E. Honda: Super and ochio cannot be stored. Throw loops based off his HP grab no longer work (but do work with his HK grab still). Sumo Smash special move may have had hitboxes altered making it a lot more difficult to use it to go through fireballs. Ochio throw currently has a glitch that allows it to grab people out of non-throwable frames (like right after the super flash). Overall well worse than his ST iteration.
Blanka: No change.
Zangief: Easier input window allows for very easy walkup SPDs (hold forward, go forward down, down, down back, back, back up, punch). Two buttons allow for a lariat instead of three, messing up using the "piano" method for getting SPD ticks and reversals. Neutral HP headbutt insta-dizzies. MK kneedrop is bugged (treated like a LK move). Currently has a glitch that allows for normal throws to get SPD range. This can also be used to give Gief Super SPD range. Probably considered neutrally good as his ST counterpart (i.e. not good lol).
Guile: No change. Easier input windows allow for new combos involving super, flashkicks, and sonic booms.
Dhalsim: Super can be used as a reversal, making him better than his ST counterpart. Teleport reversal works correctly now (i.e. won't teleport you into the same place if done as a reversal).
T Hawk: Based off N. Hawk, so shitty normals. Also cannot start a throw loop off of his HK throw, making him a lot worse than ST if that's possible. Easier input windows make walkup SPDs easier like with Gief. No longer has stray hurtbox trailing his crouching MP. Might be the worst character in the game.
Cammy: No change aside for easier input motion for hooligan roll.
Fei-long: No change. Easier chicken wing input.
Balrog: Easier input windows allow him to do stuff he couldn't do in ST, like follow up a dash upper into a dash sweep. Unknown if it really helps him that much right now. Can no longer get a safe jump throw loop off his throw on certain characters.
Deejay: No change.
Vega: Can't re-attach claw after losing it. Forced to climb his gate on his stage, making him a lot worse playing in Spain. Cannot store his flipkick by holding a back charge. Capcom said they made it so you can't juggle flipkick after landing a flipkick but it still works on wide hurtbox characters like Gief and Sagat.
Sagat: Based of N. Sagat from ST (so, pretty bad). Can use super as a reversal. Inputs changed for tiger knee.
Bison: No change.
Akuma: Can be dizzied. Takes more in damage and stun than the rest of the cast (moreso than E.Ryu/V.Ken). Cannot lock people in a corner with his HP multi-hit fireball. Ground tatsu can no longer go through projectiles. Possibly other nerfs from ST Akuma. Still top tier. Maybe even the best still.
V.Ken: Not in ST. Has a few attributes from N.Ken (crazy kicks, knee bash), O.Ken (invincible srks, better hadokens), and even HF Ken (HF style air tatsu). Has a wicked command dash that may or may not break the overall game balance. Jump arc is unlike any other character in the entire SF2 series. Walks faster than regular Ken. SRKs juggle like Akuma. Takes a lot more damage than the rest of the cast (second only to Akuma). Probably the best character in the game right now.
E.Ryu: Not in ST. Basically regular Ryu with a few new moves and less health. Differences include controllable normals (being able to use a close or far normal at your convenience, like Dhalsim). Has a new far reaching kick overhead. Has raging demon super. Walks faster than regular Ryu. Red fireballs hit multiple times like Akuma. SRKs and tatsus juggle like Akuma (SRKs don't hit 3 times like Akuma though). Currently doesn't have a juggle limit on air tatsus, which can make for easy juggle dizzies. Strangely SRKs are not fully invincible on the way up like Akuma or V.Ken.