I have both M3's and M22's. They are older, Ti versions. Have not heard M5's.
The M3's are a perfect bookshelf speaker for those areas in a home (or other space), and you just don't have room for a sub - and only want a 2 channel system.
The M22's almost "need" a sub, but sound fine OK without one. I am currently using them as side surrounds in a large room where they are about 8' away from the closest seat. When I have this system in mulit-channel stereo mode, and sitting near the M22's, I am often impressed by just how good they sound. They are a great little speaker. JohnK used to praise them all the time on this forum, saying they could compete with the larger Axiom speakers. He was correct.
