OK I read through some posts, the bottom line with PSX MKT is, it plays just like UMK3, only faster. If you use an emulator, you can modify the frame rate to 53 FPS and it will play 100% identical to UMK3 in terms of speed. MKT added some broken characters, which in turn can compete with the top tier of UMK3 and then some. This doesn't break the game, it is some broken character additions. The thing with N64 is, they changed a lot of universal things, like collision, and gravity, screwed up move properties, etc. This makes the game itself broken, not just the added characters.
Also, playable bosses = garbage!