I have a pair of v2QS8's in a 7.2 system that set almost 8' in back of the primary listening position that I feel do an excellent job of getting the sound to the listening area. I did experiment with a pair of M60v2's as back surrounds but personally felt the QS8's did a better job ... but of course what works for me may not suit other's personal taste.
thank you rickF for your input especially since you are a user of more than 5 channels and you use the QS series as back's so your opinion carries some real weight in my decision making.
i'll have to wait until after i move and get settled to actually do any installation and testing so thanks to all this feedback i'm getting i think my heads gonna blow up with anticipation!
the speaker will be here today.