Seek, the only thing that I'll add is that you've been reading the wrong stuff about receivers supposedly having trouble with the M80s. Again, the question is simply how loud a listening level. There should be no problem at levels not insanely loud which are dangerous to hearing.
Well, I get most of my information about axiom speakers here, but I also hang out on Bluray.com and I read under the axiom speakers there. I previously owned an onkyo 606 and now I own a yamaha 667. The onkyo 606 definitely sounded more powerful and truer to the wattage rating than the 667. I got the 667 because it offered the right features that I needed at just the right price. With that said, when I do get M80s, i would want to pair it up with a VP180 center. I would think that the 667 would have a little trouble driving those speakers. But then again, I haven't owned them and tried it out myself.