I never heard the m60s but I did once hear the m80s. t's better than the Athena AS-F2 speakers I heard(not lower but more detailed) and the whole Klipsch Synergy line(SF-1, SF-2, and SF-3), but not as deep or as defined as the Thiel CS 3.6s I have that cost 4 times as much(big surprise!)
even the thiels that are - 0.5 dB at 27 hz in my room don't satisfy me when I feel like I want to feel what I'm hearing. That's what tone control switches are for. But what I've come to realize, is that a lot of music made in the last ten years has no low end.
the cool thing about a sub is that you separate the bass from everything else, so you can turn up the low end that is left out of modern music without having the bloated mid bass that comes from turning up the tone controls that are behind the amp going to your speakers.
When loud low frequency effects are present in a movie, the thiels did resonate the room in a way i never heard the m80s or ANY OTHER FLOORSTANDER EVER do. but I've never seen a floorstander go below 28 hz and still have no rolloff. Again, they cost 4x as much. They're the only speakers I could recommend to someone to be used in a home theater with no sub if they want things shaking and scaring you.
For music, the m80s have more than adequate bass.