Your amplifiers should have more instantaneous power than the Denon 5000 series, I agree that they will sound vastly different when being pressed. But as mentioned, over and over again. Within design parameters (not just comfortable) the conditions must be ideal for the sound to be neutral. If I power speakers at a nominal wattage of 10 watts with a receiver the power could peak out to perhaps 100 watts from a lower frequency that occurs, suddenly the receiver is having some difficulty, but is no where near shut down or perhaps not even audibly clipping. The power amplifier ran in the same fashion can produce huge amounts of power with it's seemingly limitless headroom with its massive power supply, reservoir capacitors, and hefty output. The power amp doesn't bat an eye, it just laughs at the incoming signal, and says "is that all you got? Take this your greedy speaker". This is why separate amplifiers sound better. Class A transistor amplifiers, like the mono blocks from Halcro, can squash crap all day long and remain completely linear.