I've read a few glowing reviews on the M2s and I've pretty much agreed with everything said about them. They are clear, precise, accurate, all those good things, yet I would have a hard time recommending them. They are fine stand-ins but I just don't really enjoy them. I can crank them and all they really do is get louder (while staying clear etc) without really prompting any sort of physical or emotional response. The mildly maligned M3s (with that evil nasty 100Hz bass hump) are way more fun to listen to (I certainly won't be giving those up anytime soon). I now really understand what people (was it 2x6?) mean when they say something is a "boring" speaker. No real fault to point to, just a shrug.
My guess is that the problem with M2s is dynamic range compression when you crank them up. I was experimenting for a while switching between M2 and M60 as mains in my HT system while playing things like the helicopter crash in the first Matrix film. A couple of different guests all said essentially the same thing - boring, lifeless etc...
On the other hand if you play something that doesn't require "wall of sound" output, the M2s are almost indistinguishable from the M60s even in a fairly large room.
