Is the HK 8000 out yet? I know the 520 is. Any quality assurance problems with this unit? I really like the HK sound. I probably would be using it as a Pre/Pro with two HK PA5800 amps. What benefits/features does the 8000 have over the 520? It is quite a price jump. I currently have a Denon 3300 hooked to those HK amps.