I purchased the 521 a few days ago, to replace an old Dolby Digital receiver that only had coax and optical digital inputs (and the optical stopped working).
The receiver connects to a blueray player (sony BDP-360), Xbox 360, and HTPC.
Getting this thing set up has been a bear, but I'm not sure the avr is to blame.
Issues I've had:
1. HTPC would only send 2 channel sound to receiver. After hours, I find that for some dumb reason, the specific graphics card will not transport 5.1 encoding of any type. What the hell is the point of allowing audio out by HDMI if it doesn't allow surround encoding? Fixed by connecting to the AVR with optical.
2. Xbox 360 would not play nice when connected Xbox-avr-TV (all through HDMI). The light on the avr indicated it was getting info from the Xbox, but the tv screen was blank (although it indicated that it was getting a signal). Xbox 360 will not boot unless it sees there is video hooked up, so I assume it was having trouble handshaking going through the avr. Fixed by hooking the xbox directly to the TV, and using the optical out on the tv to go to the receiver. Luckily my TV will send 5.1 out through the optical, even if it comes in through HDMI.
3. The manual lists all of the different display indicators for different codecs, but it leaves out one important one: 5.1 PCM. I was very confused because I was obviously getting 5.1 surround out of my blueray player (in pure mode I was getting obvious surround from all speakers), but none of the indicators were lit to show what format the avr was using. It turns out I had a setting wrong with my player, and it was downmixing to PCM from DD and DTS HD codecs. The only indicator of this is that when pressing "DISP" on the remote, the avr screen would scroll "PCM." The manual makes no mention of this, and I had no idea whether it was set up correctly or not. Fixed by setting the BD player to the correct settings to do no mixing internally.
4. Had a bit of trouble getting my subwoofer to hit like I expected. I must like more bass than the MCCAC wanted me to have, as I had to increase the bass level. In speaker settings, I also set the subwoofer to "Plus," which if understand this, means that it gets low frequency 5 channel sound re-directed in it in addition to the LFE channel.
The auto MCCAC calibration made the sound very good out of the box, especially when you consider I have an asymmetrical speaker layout.
I'm happy for what I paid, but I also kinda miss the days where setting up hifi meant plugging in a bunch of RCA cables and connecting the speakers, and then cranking it.