Sorry for the delay guys. Yep...I do indeed have the RMB-1075 running my Axioms. Love it. Unless you have a large room, with good depth behind the seating area, I'd stick with 5.1, especially with the qs8's as surrounds.
If you do opt for 7.1, I'd look at getting an
Odyssey Stratos to run your M80's. If you email or call Klaus (better to call, he's not much of an email kind of guy) he will quite often have b-stock units available for FAR under msrp. The electronics are 100%, but the case may have a scratch or two.
A good idea would be to start with the RMB-1075 and 5.1. See how you like that. If you really feel the need to try 7.1, you can hunt down a deal on a Stratos and add that to the mix. If 7.1 doesn't blow you away, the Stratos will likely hold nearly 100% of it's value and you can re-sell it. That's what I ended up doing. I hated to let the Stratos go, but 7.1 in my room simply wasn't worth the added expense. I ended up selling the Stratos and moving the M2i's that I was using in the rear up to my computer room. It all worked out for the best. 1) I finally was able to hear 7.1 for myself and decide I didn't need it. 2) I was able to hear and enjoy the Stratos, which I'm sure I'll own again someday. and 3) I LOVE my M2i's in my computer room.