MAME/MESS has different goals; in particular, it strives for accuracy first and foremost. Hacks that reduce accuracy but improve playability and/or performance

MAME/MESS has different goals; in particular, it strives for accuracy first and foremost. Hacks that reduce accuracy but improve playability and/or performance are generally not accepted by MAME, AFAIK, whereas something like Dolphin would have tons of them. (MAME is fundamentally a preservation project; the fact that you can actually play the games is secondary.)