Zero's animations were redone, and rainy turtloid had very few frames. Otherwise nothing too bad compared to X4 or 5
There were some duds, but I can say that about any X game. There were however some good ones. Commander Yammark, Blizzard Wolfang, Blaze Heatnix, High Max, Dynamo and Gate were fine. Sounded like crap? I'm not sure what a giant mecha turtle is supposed to sound like but I didn't see any problem with the voices.
Besides obvious intentional things like X's sabre and Zero's buster I didn't notice this. All the PSX games are pretty sluggish compared to the Snes ones.
Can't argue with that.
There are other measures, such as quitting the level or killing yourself or moving offscreen. I'm not saying it's great but there are ways around it.
EDIT: Oh yeah and the shadow armor, that was a cool armor.