Hi darbo. Yes, the M80s can handle tremendous power, more than their rating of 400wts suggests. Axiom has tested these speakers at 700+ watts continously for 24 hrs and to give you some example how much power they are capable of, at the Axiom gathering which concluded at Ian's boathouse on Lake of Bays, the live band there was playing through 8xM80's and 4 Axiom A1400amps over the Bay...it was loud AND clear!! if you give them the power you'll certainly have no problem filling your large room.
Some of Axiom's designs are different from the "accepted" norm such as dual tweets or slightly different arrangement of their drivers(as in the VP180) but they spend many hours blind testing various designs including the "conventional" ones and if the "unconventional" design sounds better in the blind test then that's what they go with. I personally like that fact myself. Axiom recently brought on board Andrew Welker who was the chief designer at Mirage. Have a look at some of his designs like the OMD 15's or 28's....certainly not "conventional" but brilliant designs.
Trust your ears!
