I am sure the M3's will play better than your current speakers, but to really fill the room, floorstanders are the only way to go.

The sub will add the low end punch but the main music could get drowned out.

You should try to audition some Axioms just to see what they are like. Check the Hearing Things forum for the audition list. If no one near by post up that you are looking for an audition in your area and send Amie a PM to see if she has some one listed but not on the list yet.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70