Adcom = High current for low impedance speakers == Great Sound for the money

Some other reviewer commented saying Denon AVR3806 did as much or better than Adcom at less than half the price. If you look at the specs of Denon, it cannot drive 4 ohms speakers for example. People who have such speakers as Magnepan, Martin Logan etc have speakers that require a high current amplifier to drive these speakers at 4Ohms or less and Denon fares very poorly in that respect (I have had a Denon and an Adcom and I know the difference it makes to my Martin Logan speakers).
If you have normal (not high end) speakers such as the standard Polk, Cambridge or other such speakers that use the diaphram/cones you are probably ok with Denon. But once you go in for real high end speakers and look for a good soundstage and fidelity in classical music, you better also go for a good receiver.
Adcom is known for huge power and very good fidelity/reproduction of music without any (perceivable) distortion and they stand by it. (disclaimer: I don't have any ties to Adcom - just an end user)