I originally was going to get the M80s but the 4 ohm thing was bugging me. Joe at Axiom told me they sound about the same except as Chesseroo noted above. I love the M60s and they have been playing all day, every day, for the past 3 weeks. Two trays of CDs per day, and a movie 4 nights out of the week. I'd like to have the M80s, but with that much play time maybe I made the right choice?