Still some games are a bit slow but playable : Tekken 2&3 (the worst both), crash team racing, crash bandicoot, Ridge Racer type 4.
Gran turismo IS perfect. But thé 2 IS completely buggy graphically.
Great optimisation speed are :
Vidéo Sync off, audio Sync off, scan Line interleave forced on (Tekken 3 Can be), frameskip 1.
All final fantasy are playable in good condition. G-force effect of ff8 are a bit slow althought. Every smoke effect are perf kill.
I forgot to mention : update to lastest luma cfw for best compatibility + original psx bios + chd format (very few crash exception then). Chd converter IS downloadable from Mame archive.