I've had mine for a while now and I love it. Recently went with 7.1 setup from a 5.1 setup and I love how well PLIIx works for games. Its really really good. Dead Rising, Half Life 2 and Bioshock were stunning with the surround channels and the movement to my side and behind me was very accurate and seamless.
This also helps to an extent with height perception in the rear, and crowd sounds during concerts. It really does feel like I am part of the audience now and when a chopper arrives behind me from above, its accurate. Good stuff.
My setup is
Panasonic 42 inch Plasma
Infinity Primus P362 fronts
Infinity Primus PC250 center
Velodyne VX10 sub
Yamaha NS225 Surround and Surround back
PS3, Xbox 360, Philips 1080p Upconverting player, Sony SACD player
I've setup the surround back Yamaha's behind me on tiny wooden stools called milk stools that I purchased from Lowe's to keep with Dolby 7.1 speaker placement recommendation. The surrounds are at 90-110 degrees to my side.
Let me just share some notes.
Sound is very good, no issues there. I cant add anything about sound that hasnt already been said here.
Crossover accuracy isnt very good with this receiver. The cut off curve is not very steep and sound is definitely better with speaker size set to small instead of large. Large has the subwoofer firing as well as the fronts, so I am not quite sure what the idea is there.
Subwoofer level has never gone above 10 for me.
PLIIx modes are very useful for 7.1 and use it as per the media you are watching. its very self explanatory since the modes clearly say Movie, Music, Game. But the modes are very useful in sound placement and creating a seamless audio field around you.
I dont quite like NEO:6 as much
LPCM from PS3 is the only way you are gonna get HD sound from PS3. Unless you have the new Slim PS3 which supposedly can bitstream HD audio thru HDMI.
Xbox 360 just makes every Dolby Digital 5.1 which is absolutely attrocious IMO. Its not a solution for a proper home entertainment system if you are serious about sound.
The auto setup is pretty useless, and I think this has been mentioned before. I suggest you take a tape measure, measure the distances to each speaker and set it up and play around with speaker size and crossover settings and individual levels till you are comfortable.
From what I can tell, universal remote cant switch from BD to BD8ch mode. This HAS to be done with the Panny remote since you need to hold down the BD button to switch to 8ch discrete inputs (which I use for SACD). The other issues are that harmony does not fill up the menu items with sound menu and option menu. You need to add those in manually. The inputs also have to cycle one by one unless u add shortcuts to those.
I have had my menu freeze up a few times when I try and move around it a bit quickly, nothing that can't be fixed with a quick restart, however it does happen.
Compression levels are decent, Standard compression doesnt ruin the sound as much as some of the other receivers I've heard.
I am always impressed by how light weight the receiver is, since I have had to rewire it quite a few times for various configurations.
The manual could have used a little more detail on sound modes and specifications instead of a one line explanation for most of them
I have a ton of headroom left which is good to know. I was always close to maxxing out the Sony receiver I had before this.