I own M3's and I've listened to M22's in the same spot as well. They are both excellent speakers. The M22's definitely have a more forward (midrange) sound with the dual 5 1/4's and the M3's have a much warmer and laid back sound. While some would point out the freq response of the M22's goes lower than the M3's I can tell you to my ears (and others in the room when we were switching back and forth) the M3's low end was much more impressive with it's 6 1/2 inch woofer.

If you plan to always use the sub with the speakers I would recommend the M22's. If you like to play some 2 channel music without relying on a sub you may want to consider the M3's.