I have a pair of M22's that I've had for maybe 6 months or so. I would characterize them as "detailed" rather than "bright." I drive mine with an Audio Refinement Complete Int., which is one of the "warmer" sounding SS amps that I've heard, so it's a pretty good match. I imagine tubes would compliment these speakers really nicely. I was a bit worried buying the Axioms sight unheard (factory direct only), but the 30 day no risk, free trial, won me over. Give 'em a try, as in mics., only YOUR ears can tell you what you like.
Matt