M2 a bit more accurate then M3, M3 goes a bit lower … the M2 needs a sub (IMO), The M3 would benefit from one but can stand alone.
As far as subs go … I’m sure anything in the axiom line up would work … I’ve only tried them with a 500 and an old (1990?) Mirage Sub. The 500 is a killer with the M2’s … the Mirage sub although passable … just didn’t compare with the 500 combo. Your results may vary …