Te, I'm sure that the scientists among us will be able to cite some psychoacoustic paper on the topic. My understanding is that people perceive "louder" as "better" up to a certain volume point. That concept is not specific to any particular brand or model of speaker. The M80 should sound as full and rich as anything else at lower volumes; they don't NEED to be driven to high volumes to sound good, but they CAN be. My experience (not science!) is that the M60's sound very rich and detailed at low to moderate volume levels, and that they also can provide very satisfying, large-room-filling sound.
There ARE good people here - people I now call friends. You should stick around and keep us posted. I'd love to see some pictures of your room, and I'm sure you have expertise in many areas that we can all learn from.
