There will be a change if you use a more powerful amplifier. But it is a controversial topic around here! :-)
For my two front M80s, I use a QSC SRA 3622 amplifier (1100 watts x 2 @4ohm). More info here:
http://www.qscaudio.com/pdfs/sraspec.pdf
For my two rear M80s, I use a Carvin 1800HD (600 watts x 2 @4ohm). More info here:
http://www.carvin.com/products/single.php?ItemNumber=HD1800&CID=PWA
The QSC amp's fan is silent. The Carvin amp's fan is just barely audible if you stand within a few feet of the amp.
I am using the Denon 3805 for the VP150 center speaker. But I might get a separate amp for that one too!
Using separate amps has made an audible difference when I listen to music or watch movies. The headroom provided by the amps makes a significant difference to sound effects in movies. YMMV.
