I wonder if a couple M3's would have solved your rear sound field dropout problem in your old 7.1 setup. Do you not have that issue now?
There was no problem, 5.1 worked just as advertised. I tried both M22s and QS8s as back speakers for 7.1 but the PLIIx algorithms just aren’t that good at handling hard pans in video games, plus the QS8s as surrounds are just so good that my experience is with proper placement they negate the need/benefits of rear speakers in many situations for discrete 5.1 material.