I think it has more to do with personal preferances of music than the speaker choices, which are usually decided on by money and receiver options(4Ohm load of the 80s). I prefer hard rock metal, pop but have branched out to some jazz and classical thanks to the suggestions on this forum.
The sound from M80 to M60 is very subtle and unless A/b'd most would not notice a difference. I had M60s and M80s and A/B'd them several times and the M60s are slightly more laid back than the M80s, IMO. I found the differences negligible for movies.
