I have to admit that the RZ820 looks great aesthetically - sleek, big (8" tall), and heavy 31LBS.
If you don't care for Audyssey Dynamic EQ or dual SubEQ or XT32 and as long as you have good warranty, $559 is mighty tempting for sure.
Just looking at the big thing makes me want to buy it for $559.
But because I personally must have Audyssey XT Dynamic EQ, I have to stick to Denon, Marantz, and especially that gorgeous $7,000 McIntosh MX122 Pre-pro with Audyssey XT32 Dynamic EQ.