What do you mean by Difference?crisper, more details? M80s would give you a difference that is guarranteed to make you notice at all volume levels compared to the M60s.

You will find a noticeable difference at louder volumes and less so at lower volumes, or so those that have larger amps have posted. Is it worth $1000-1500, that's your call.

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