I use 1 QS8 as my rear center in a 6.1 setup and I think it helps spread the sound out better across the back. I would think that in a 7.1 it would be wise to use M2's or the like as rear centers as they are spaced apart like the front mains and dispersion is not a problem. I would use QS8's or 4's as side surrounds again for the dispersial factor. I believe these are the more common ways of 6.1 and 7.1 setups.


Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70