I'd say you made a good choice. The Denon 4000 range is much closer to the Integra line than the Onkyo. It is near the flagship AVR product as the 5000 range is well into the separates price range. If I was you, I would not give it two second thought. I'm looking at the 3000 line and that gives me some pause as compared to the Onkyo 876, and Integra 7.9. But the Denon 4000's are great equipment. And the video is very good, just perhaps not as great as the Silicone Optix. But if you have a good original signal (BluRay etc) then you won't need to scale up the signal so no problems. Enjoy.
But...if you change you mind, I'll take that 4308 off your hands for...a few mardi gras beads? I'm sure you dont' have any of those.
Panny 3000 PJ, 118" Carada, Denon 3300, PS3, Axiom QS8, PSB 5T, B&W sub, levitating speaker wire