I did a head-to-head audition of 3 of the towers, and have heard the M3 and M22 head-to-head as well. With the M80s and to a lesser extent the M22s, the mids and treble are very crisp and prominent, but not what I would call bright. Admittedly, this sort of effect isn't for everybody, in which case you might want to check out the M3s or M40s, which are laid back and not bright at all.

As I upgraded my system, I found oddly enough that the biggest difference maker for brightness and warmth with music was my receiver. What electronics are you using?