I noticed that the M80s played with more detail at lower volume levels than the M60, once you start to increase the volume, say near reference levels, the differences went away. I have my M80s in a 12X16 'L' shaped room where the other part of the 'L' is also 12X16.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70