Well, I was able to do some comparative listening last Sunday. It was extremely unscientific: I did not set the speakers up so that I could quickly A/B them, I did not rotate each speaker into the exact same spot for the listening tests, I did not do the listening tests blind.

I did, however, have the dog wandering around inside - occasionally parking his smelly self in front of the speakers. I also had the little boy in my avatar playing with Hokey-Pokey Elmo for much of the session, too. Extremely unscientific.

Anyways, here's Elmo with the introductions:

http://img.photobucket.com/albums/v155/bigwill/DSCN0980.jpg

And here's how the speaker cabinets vary in size:

http://img.photobucket.com/albums/v155/bigwill/DSCN0978.jpg

And here's a side view of the Silver 8 in the Rosemah finish:

http://img.photobucket.com/albums/v155/bigwill/DSCN0976.jpg

And here's how I had them set up for listening (Axioms to the outside ):

http://img.photobucket.com/albums/v155/bigwill/DSCN0981.jpg

I listened to the same 10 songs or so on each speaker - one at a time, of course. I jotted down notes as warranted. The difference in "in-my-room" sensitivity was negligible; the MAs may have been a db or half a db louder, but nothing too significant for the way I was demoing them. I do tend to crank them louder than my M60s when listening to music, however.

I'm sorry for the dearth of factual info in this first post, but I left all the listening notes at work. I'll try to give a thorough dissertation in the morning.

My overall impression was:
-the Axioms did more than hold their own;
-the S8s are a little "better", but maybe not $400-500 better;
-my ears had fallen prey to suggestions that the M60s are "bright", "thin", etc...;
-if you like the MAs you should like the M60s;
-the M80s in a high-gloss finish would have been a great comparison;
-I like the fancy mahogany veneers on the S8s;
-the S8s have deeper bass, better bass, a bit more midrange, and a little more forgiving tweeter, but crappy recordings still sound like crap on both speakers;
-I love both speakers. I kept thinking, "Life is good," over and over and over.

And a PS to TNTguy: I have no idea about MA's policy toward speakers purchased from unauthorized dealers. And for HT, they seem to blend superbly with the Axioms - particularly the VP150. The S8s seem to call less attention to themselves in HT, but you do lose some detail.