For what it's worth...
The Pioneer is rated THX Select - plus. The Denon, had they paid the fee, probably would have quailfied, but wanted to keep costs down. Denon weighs in at just under 40lbs. Denon has a better name in the audio industry. Pioneer's Elite brand wins a lot of "low end" audiophiles over. They both are pricey. The Pioneer's are known for "in your face" sound as opposed to a more "flat" sound from the Denon. Both excellent units. I pick Denon for the sound.