I too went from a Sony to a Denon and the difference was very noticeable. I can remember thinking the dynamic range was better with the Denon, which would mean the Sony was very under powered for the volume levels I wanted. The Sony seemed to have a much flatter playback less noticeable highs and lows than the Denon.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70