(raises hand)
One of the tests I ran when people came over to see the system was switching between M2 and M60 mains, with everything else (VP100, QS8, sub) staying the same. I did adjust speaker levels though.
Consensus was that the M2s would not play loud enough in my (large) room if you really like to crank the volume, ie if you are one of those people who says "listen to *this*" and reaches for the volume control for scenes like the helicopter crash in the first Matrix film.
For "normal HT purposes" I agree that M2s will play loud enough
