What is the difference between speeds in SSF2T

I really dont see a difference. they all seem to same to me. I noticed online most people prefer turbo 1, is there a particular reason for this? how does different game speed affect the game?

The default (and thus officially used) offline speeds for Super Turbo is 3 for the japanese version and 2 for all other versions. For whatever reason a lot of online players think the emulated speed of turbo 1 more accurately matches the offline speed of turbo 3 (I’m talking about the japanese version currently featured on Fightcade). To me personally it feels slower than arcade but you get used to it.

It seems the difference in speed among stages is sometimes greater than the difference from changing it the settings menu. You often see Japanese commentators mentioning Claw’s and Dhalsim’s stages, due to how fast they are; and Honda’s, due to how slower it is.

Game speeds affects everything in the game. Faster speeds makes whiff punishing more difficult, less time to react to jump ins, etc… Slower speeds have the opposite effect. Tournament standard has been US-2 or JP-3 for quite some time and it’s a pretty happy medium between a super fast game that’s fun as well as a slower game that rewards strategic play and counter uses.

Even some stages run faster or slower than the standard speed based on how the game is programmed. e.g. Claw, Dhalsim, Zangief stage runs faster and Ryu, Honda, Sagat stage runs slower.