One thing good about the Denons is that their amps are quiet. You can select a source without playing anything, crank the volume right up and you won't hear any hiss even if you stick your ears close to the speaker.
Based on your less than perfect experience with the 3808 it is good that you are able to exchange it for the Pioneer and that you like what you hear so far. I am still planning on getting another Denon but have not completely ruled out the Pioneer yet. I would appreciate it if you could find out whether you can hear a hiss from the Pioneer by selecting a source with nothing connecting to it and crank the volume right up to, say, pass 0 or higher.