I won't quibble with happy M80 owners, even if they are overcompensating for something. I've heard the M80's; they are great. I have not lived with them, however.
My understanding was the M80's would deliver the highest quality sound, even at low volume, but that the M60 required more volume to sound almost as good. The M22's are missing a midrange speaker and therefore someone said that it was also lower in midrange quality.
I don't think either one of these things is true at all. I regularly listen to my M60's at sensible volumes and I think they sound great. M22's plus a good sub is a dynamite combination, especially in a relatively small room. There are MANY audiophiles that believe no floorstander can compare to a monitor style speaker for imaging.
Do not underestimate the sheer size of the M80's. They are very deep (unlike some of their owners). That alone could restrict your speaker placement options considerably, and how your room interacts with your speakers is really very important.
M60 Posse Member