I'm a beliver in what you heard..I had been using an Onkyo 801 as my AVR. Recently I purchased a 5-channel amp and now I'm using my Onkyo as a pre/pre and oh my gosh imho it made a wondeful difference in all 5 channels. For me its like a veil was removed from my speakers. I have my M80's set to large - I hear better seperation of sound with that setting on my system compared to small setting.

M80
VP 150
QS 8's
Onkyo pre/pro
Halo A51 5-channel