Your M80s may be v4. If they're any older, putting them side-by-side with the M3v4 should make you want to burn the M80s!
If you have the M3v4, any v4, set up properly in your room, you will hear a deep and wide soundstage with layers from front to back. This soundstage is behind the speakers. Just freakin' unreal!
I have them in my 12' wide living room, with their baffles 4' away from the front wall. They are 8 feet apart and I am sitting 8' away. The back wall is 8' away from me. I could listen to them forever!
A-LFR/1000-8 & 2/500v4x2
Air Force, Freedom