Group hug?
I seriously love the M9. I am a gear freak and change amps all the time, but this one is here to stay. I even bough a brand new M9 immediately after my first (used and older version) M9 died. Normally, if an amp dies on a gig, the brand would be dead to me forever... but the M9 just sounds so damned good, I had to get another. BTW, it has performed flawlessly since I bought it a few months ago (I play and gig a lot).
My bandmembers LOVE the amp also, but HATE me always talking about how good it is! "So... enough about my Mesa M9.... let's talk about my Mesa M9"!
P.S. A/B it against other heads if you can for fun. In the last few months, I A/Bed the M9 and an Ampeg SVT-II Pro (sold the SVT immediately) and a TC RH450 (no contest... the TC was on Craigslist the next day).