The 5th installment of the Street Fighter II sub-series has stood the test of time, and is seen as one of the best fighting games of all time, in spite of the balance problems that it has. The game speed is faster like in Street Fighter II' Turbo: Hyper Fighting, several characters gained new moves, and Akuma makes his debut in this game.
When Super Turbo was first released roughly 5 months after regular Super Street Fighter II, people were getting bored of Street Fighter II in general. But the game has since become popular between Japan and the rest of the world. The game is still regularly played on Fightcade, along with Champion Edition to this day.
As a lot of us have noticed, playing against the computer in this game feels nothing like facing an actual human opponent. Most of the time the computer will perfectly respond to your every move. It may become even more apparent after the first opponent is defeated, as the game will then set the CPU player's internal power level to the highest. By "power level", I mean the computer has stronger AI while doing more damage, and receiving less damage than you. My guess is that Capcom wanted the CPU to use a higher power level for other regions, but they made a mistake in the assembly which was not fixed in the Arcade release of Hyper Street Fighter II, either. The computer is also known to cheat in ridiculous ways, such as unrealistically fast button mashing, a prime example being Zangief snapping out of dizziness in only 3 frames. The CPU might even have faster frame data on their attacks, like Dhalsim's Close Crouching Medium Kick. The only way to reliably beat the CPU in this game is to somehow understand parts of their AI scripts and take advantage of the things that their AI is weak against, like Chun-Li's Neck Breaker against certain characters.
Should you go up against actual players, the vast majority of them will still tear you apart with setplay crossups and such.