ajb,
I understand your concerns but really, don't be TOO concerned.
Here is a link to my basement situation
my basement
As you can see, the M60 on the right is in a rather limited area very close to 2 walls. Although there is something of an echoed effect off the wall (it is wallboard on top of cement behind it) i certainly can say the sound of the M60 is just fine.
I also tested out the M22s before i had the big screen tv and for music, they just didn't fill out the room enough for my liking. They would have been perfect if i were only using my system for home theatre. Other than that, they will sound alot like the M60 with the exception of the bass extension as i mentioned in a previous post.
