A little late to this thread, but I'll chime in anyway. I have both the M3s and the M22s. I bought the M3s first (a blind buy, for my son) and loved them. I went with the M3s beause he does not have a sub. After hearing the M3s I wanted to upgrade my speakers, and since I couldn't very well have the same speakers as my son I got the M22s. I was amazed at how much difference there was between the two. I had assumed the difference would be slight, I was wrong. I definitely liked the M22s better. They seemed "cleaner"; which was probably the lack of the mid-range bumb some people mentioned. I'm using the M22s with a sub, but I did the comparison with the sub off.
