~630 for the 2802 is not a good price. You can routinely find it for ~525 if you look around. For ~$100 more, you can get a 3802, or you could just wait a little and go for either the 1803 or some other model. But if your budget is not over $650, go for the 520
I like my H/K AVR 520. I didn't look at (or listen to) the Denons when I was shopping for a receiver. But as I've since found out, the 2802's and 3802's only have 1 digital coaxial input and the lowest you can set the crossover frequency is 80Hz. So the Denons wouldn't have worked for me anyway. But if you can live with the Denon's "limitations", give them both (Denon & H/K) a listen and decide which one sounds better to you. Good luck.
My favorite receivers are the Sony ES line and the HK line. Denon and Onkyo and Marantz(never heard) can go squabble in the number one contenders match.