Just to throw some more confusion into the mix...
I drove my M60's for the past 5 years with a Yamaha RX-V1400 and I think it sounded great. Lately I started looking at getting even better sound and I was looking at the M80's. Instead I purchased an Emotiva MPS-2(now discontinued) to try things out. To make the story short, the M60's were transformed. The lower bass is so much stronger and so much more detail as well, they just feel alive. I've been listening to music without a sub for the last two weeks and honestly I don't feel like it's needed(movies excluded).
The Yamaha by itself could play to insanely loud levels without breaking a sweat, but now I can listen at 75-80db and the speakers sing with enough bass to make my hardwood floors vibrate. Before I had to play at much higher db level for the same "sound".
I beleive the newer receivers like the 3808 will prove better than my 5 year old Yamaha though, and the difference between it and a separate amp might be negligable. I have not heard the newer ones though.
