I'd rank the Classics like this:
Mega Man 2
Mega Man 9
Mega Man 7
Mega Man 3
Mega Man 6
Mega Man & Bass
Mega Man 1 (Nostalgia makes me want to rate it higher, but it wouldn't be just)
Mega Man 10
Mega Man 4
Mega Man 5
Mega Man 8
So MM & Bass is right in the middle. It has its good points, it has its bad, and they even out enough to make it a middling experience in the series.
Even though it's been a long crazy time since I've played 5 and 6, let alone I never finished them or have even played 7 yet, I'll throw down my list for the rest of the games in the classic franchise.
)
just playing of course. I must be tone deaf but I never noticed a difference in the sound effects. I never play the game on Navi and I hear the sfx are different.