donaldkelly - I own M22's and just received a pair of M3's today. I set the M3's up on my screen porch as a zone 2 speaker.
Although I didn't do any serious comparisons between the two, I have lived with the M22's for awhile and noticed the difference with the M3's right away - better bass response (when comparing without a sub), and an overall warmer feeling.
I spent several hours today with the M3's playing some background music while I did some reading. My wife and I sat on the porch talking about the day and the sound from the M3's was really soothing, without being muddy sounding (of course you probably know this from your own experience).
The M22's, as has been said so many times before, are more forward sounding, and because of that they sort of command your attention. Great when you are trying to pay close attention to the music or a movie. But don't get me wrong, they still sound good for background music but already I think I prefer the M3's for that purpose.
Btw, I have a sub - an Outlaw LFM-1 - which integrates extremely well with my M22's so there is nothing missing from the bottom end when I listen to them.
Hope this provides a slightly different slant on the comparison between the two speakers. Probably the best way to choose is to think hard about your listening habits - do you like to do a lot of active listening (go for the M22's), or do you like to be involved in other things while the music is playing (keep the M3's).
For HT I bet the M22's probably would beat the M3's hands down. Maybe I'll swap them around just to see.
