My 2 cents....
I first purchased the M22s. The sound was wonderful, but there was something missing for me, even w/ a sub. I then picked up a pair of M60s and confirmed what I had been feeling. Even w/ the sub, the M22s could not compare to the M60s. The M60s just cover the range and fill the room much better than the 22/sub combo.
I'm not trying to stir this up, but I wanted the original poster to get an unbiased opinion. Sometimes people post here stating that there isn't much of a difference between the two and I get a little frustrated. The M22s are a great set of speakers with a wonderful sound, but they are still bookshelves. They just can't produce the same robust and satisfying sound as the 60s...nor should they.
Again, just my own two cents from someone that's done the side-by-side on this one.
