I have a Mesa 400+, which is an extremely loud and rowdy all tube head approaching 485 Watts. Its good for rock and blues with a little grit and growl, but its not a very subtle amp, more of a pants flapperlaugh: lol- for sure)! I've played a Mesa M9 only in a store thru a new J bass ( can't recall the cabs) but I keep coming back to that day in my memory as a very happy one. Seemed easy to dial in tone to die for. And finally the amp I've read so much about but have'nt found out here in the boonies of Iowa to play on yet- the Mesa D-800. How would you all compare these three amps? I know that the 400+ IS GOING TO BE TOTALLY DIFFERENT! Part of me would like to try something different and another part wants to keep the 400+ because it is different from my other amps( Mesa Titan, GK RB1001, TC Electronics Classic 450). And why was the M9 discontinued? Any suggestions? Please feel free to throw other amps into the mix (I'm esp hearing good things about the new Genzler Magellan 800). Thanks. DAcat.