Unfortunately, the M40s are about the least discussed Axiom speakers here on the forum. Anybody got any direct experience with them? Anybody? (I keep hearing an echo coming back to me).
If all else fails, you should give Axiom a call, describe your situation (i.e. room size; budget; etc.), and what you're looking for, sound-wise, and ask them their recommendation. They are very nice people, will be more than happy to help you, and will not try hype you into something you don't need or want. They just want a satisfied customer. It's worth the money spent on the call.
"People generally quarrel because they cannot argue." - G. K. Chesterton