Dave, you appear to be paying too much attention to relatively minor differences in maximum power ratings.
Yes, I do have that 'problem'. I am sure my ear is much more in the "I could not tell a significant difference in normal listening level SQ between 90w and 130w", vs. the camp of folks with more distinguishing ears. I'm working on letting that go.
I had the M60s in my house for about a month before the M80s arrived and a couple of weeks after the M80s arrived. I liked the M60s even more once I stopped comparing them to my M22s and any other speaker I could find. \:\)
What was your story on why you ended up having both pairs come to you? Which ones did you keep (or can you say! :D).