Well, I got the 663. It is a great receiver. I did run into two minor problems. First, for some reason my remote was not working when I went to edit the inputs. The arrows would not work. I just had to have the amp button activated, nothing big, but stopped me for a while.
The second problem I ran into is that I connected the component and hdmi as video outputs to my tv. I am able to get the hdmi video, but not the component. I e-mailed Yamaha. This might be a hdmi priority thing. No big deal if it doesn't, I can just plug my 360 directly into the tv.
Sound: It is amazing. DTS HD and Dolby HD tracks are incredible from my ps3. The system even sounds just as good as my old expensive Yamaha receiver which introduced dolby digital. I did run a side by side comparison of bitstream and lpcm mode on a dolby digital dvd. I used Fleetwood Mac the Dance as test. They basically sounded the exact same. The only difference was that I had to slightly increase the volume by five notches more with lpcm than bitstream. I'm glad I am able to get the exact same sound. Makes me happy for things like Dolby TrueHD where I don't have the equipment to bitstream dolby true hd to the receiver. I highly recommend this product.
One last thing, the speaker connections are kind of close together on the back. If you are skilled in wiring, I would recommend using banana connections. I ran the old fashion way and it took a little while with my fat fingers and short speaker cables. (New entertainment center that really cut the slack on my speaker wiring.) Thanks for all your help.
One last little comment. I may not recommend buying from that seller on ebay for $349.99 and free shipping. He makes you have to sign for packages from UPS. I just became full time and work 9 to 5 so I miss the ups guy. I had to drive an hour into downtown at night to pick this up since that was my only realistic way to get the item.