JohnK,
I agree with you to some point. However I don't think MOST (I’m not saying all) receivers can push a system adequately (all channels driven). I can hear audible distortion with the Denon (and others) receivers that I have ether owned or installed at reference levels. Keep in mind that the speakers where not as efficient as the Axioms either. One way to tell if the receiver is being taxed is throw in you favorite CD and turn it up to your reference level, if the lights DIM on the receiver during peaks then you receiver is being taxed and more than likely distorting during those peaks.
The average listener may not be able to hear a difference. I certainly can.
If I were to upgrade to the M200’s I would stick them on the mains and let the receiver handle the centre and surrounds.
This is just my opinion and personal experience.
Tom
