MAME4ALL will be smoother than sdlmame or mame on N900, but it's just for some games, such as cps1.

No games that MAME4ALL can support but mame cannot, if it does, that's cause you have not use the correct rom, you should check your romdat.

btw, some hack roms, such as wof, probobly not be supported by mame or sdlmame, but supported by mame4all and fba. that's almost in cps1

I don't think our N900 needs a mame4all version, we just need fba can use a savestate, or a higher version of mame like .143u7