I'd just like to add that if you can fit the M80's or M60's within your aesthetic demands, they both play very well at low volumes. I have not heard the M80's personally, but I listen to M60's daily with both movies and music, and find the M60's to be very good at low levels. Everyone says that the M80's do a better job on top of that. So just because you don't want to use the M80's to bring down the walls in your current house, doesn't mean they won't still play spectacularly at lower volumes.
That said, the M60's just are awesome when I blast them at high levels, haha.
In terms of receiver, if you are going the Onkyo route with M80s, I would suggest staying at or above the TX-SR7xx level at the least. If you stick with anything below that (M60 or M22), than even the lowliest Onkyo makes serious music.
