I was starting to worry about the M80 being too big too, so I called Axiom and talked to J.C. He said given the size of my room I could definitely go bigger than M60s. I'm not sure I mentioned my sitting 13' away. I'm still a little nervous about the M80 though, but that's countered by my always wanting a pair. Your experience chesseroo swings it back a little. If you find your post I'd definitely be interested; I'll be poking around too.
Given the feedback I've started to swing to the LFR660's again. (There's about 8 swings remaining!) I'm just not crazy about double the cost. And the set-up: I already have wires running for a standard pair, but I'd have to run two more lines and set up the amp 6 feet away from my receiver and run those wires for the omnis. Not only am I very lazy, but I can't be crawling around on the floor and in the basement right now. So I'd have to tell my wife that I'm just setting the amp up in the living room "for a bit to test them out", and see how long I could get away with that. Also, she wants to get a cat, which I've been fending off; but if there's an amp in the living room I'll be helping to name a new friend.