George, amps don't make things sound better, they amplify what is fed to them, which is why there was little difference between your 2 Denons. No different than my 2805 versus 3808ci. They both have decent amp sections.
As Dakkon mentioned, more power will get you a little bit further without straining or clipping, that is if you even use that extra power.
Understand by doubling your power (for ex. 100 to 200 watts) only achieves and increase of 3dB. There are some other variables like room size, placement, etc. that can affect the outcome, but this mathematical equation is good to understand.
There is a lot of topics that could take this into different directions (for ex, capacitance amount, damping, etc) which can vary from amp to amp, but for normal listening at moderate levels you most likely won't hear a difference.
With that said, I like Outlaw amps much more than Emotiva, long story.