Pay relatively less attention to tests of five or more channels being driven simultaneously at full power; this isn't a realistic scenario for home use. The various channels aren't called upon to simultaneously operate at high power levels. In the 575 report give more weight to the numbers listed for operation with two channels driven, which is the basic standard(and the one used by Onkyo and the majority of manufacturers) required by FTC(Federal Trade Commission)regulations which all receivers/amplifiers sold in the U.S. must follow. Manufacturers are free to follow a more severe "all channels driven" measurement standard if they choose, but again, this isn't especially meaningful in real world use.
I use the M22s with a EP500 sub, which fully satisfies me. The main difference between the M80 and M60 has been said by Alan from Axiom to be that the M80s can play slightly louder with low distortion and have slightly more extension in the bass, while the overall sound was judged to be nearly identical in blind listening tests. Some board members have compared them recently and reported that they heard more significant differences.
