The M3's and M22s have a slightly different sound from one another. The M22s are a little more forward sounding. this means the midrange(vocals etc) sound like they are in front of the music, while the M3s are slightly laid back meaning the midrange and upper frequencies are slightly less noticeable. The M22s will also play slightly louder and IMO, cleaner at lower volumes. I found the M22s to be more detailed when played at lower volumes.
You take the entire space into consideration, especially for lower frequncies, as well as the listening position. If the listening space is only 10x10 you would be about 6-8' away, so either one of the 2 speakers you are looking at would work nicely.
