"You gotta reach for them high ones" \:\)

This 'Fan Boy' ;\) says the M60s should suddenly open up at higher volumes, that open/airy sound is what the M80s achieve with low volumes. Listen for it during the demo, if you are able to crank them up. The 60s sound quite nice with low volume, then you reach a certain volume level and the soundstage opens up and the details really start to become more noticeable, this would be the sound that the M80s achieve at lower volume levels; at least that was what I found during my comparison, beyond that they are very similar.

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