grolschie: Another thought. From what I read, double the power/watts doesn't mean double the volume. The difference between a 90w amp and a 180w amp is about 3dB. 6dB is twice as loud, so you'd need 4x the watts to double the volume - not that one necessarily wants/needs double the volume.
Why do I mention this? Well, I reckon there would possibly be very little difference in power between your current amp and the Denon. I guess that also depends on the power supplies on each receiver being able to deliver the required power when under load, multiple channels driven, etc.
Interesting.. the words I'v read and been told about the Denon is that it will deliver cleaner power than my Yamaha one. I will have to listen to the Denon AVR before I buy - no question about it.