Most likely you would find a richer sound with the M3 as it has a bit of a Bass bump with larger cabinet\driver and tuning.

My first Axiom was M3 and second set was M22. Never heard M2. My M3 plays deeper than my M22. I also highly regard M22 for any surround position. My M22 have been front on wall height 5.2.2. position for a couple years. DTSX everything the sound stage is massively awesome.