For several years, because of space issues, I always used bookshelf or similar type speakers(Paradigm Studio 40's) in my main L/R configuration. I later replaced the Studio 40's with a piano finish pair of M22's. I must admit, although both of these speakers sounded excellent, when it came to the upper bass frequencies, they seemed to be straining a little at loud volumes. Once I was able to change my set-up, I purchased a pair of M60's and the difference was noticeable immediately. I found, believe it or not, that the full range reproduction capability of the M60's blended better with my sub woofers(I have four) in that I was able to lower the crossover point, up the volume of the subs slightly, which enabled me to take advantage of that REAL DEEP BASS.
This was my experience, so if someone has the space to get either M60's or M80's as your mains, you certainly should notice an improvement for BOTH movies AND music.
