Ok, a few more games tested:
Bangaioh
Interpreter: black screen
JIT: black screen
Beetle Adventure Racing
Interpreter: very slow
JIT: slightly faster but not playable, graphic ok too
Doom 64
Interpreter: Super slow, crazy graphics
JIT: little faster, graphics still bad (can't play)
Pokemon snap
Interpreter: slow but ok
JIT: faster, almost playable
Rayman 2
Interpreter: super slow, missing some missing effects in menus and cinematics
JIT: same issues, slightly faster, but still unplayable
Tetrispere
Interpreter: slow, graphics ok
JIT: much faster/smoother, quite playable
Turok
Interpreter: not bad overall, still sluggish
JIT: looks good, plays good so far! (controls are lacking, cant get far into the level to test further)
It's interesting because some of the games I expect to run well don't, and some ran better than expected. So far I haven't found any cases where the JIT performed worse than the interpreter, so good news I guess. I'll keep testing!