I use both an 811 and 510 on my Sammy HL-P4663W DLP monitor. I'm using the 811 with s-video, Component and DVI connections. The 510 only has the s-video ouput. The bottom line is, if you are going to watch SD, the 510 has a better picture period. It doesn't matter what output you use on the 811 or what settings you change on the DLP. The 510 blows the 811 away on SD.
As far as HD, the 811 looks pretty awesome. Usually, I use the DVI output when viewing HD. It seems that component is close to DVI as far as picture quality, but component provides a brighter, more vibrant picture. I have had a few problems with HD channels becoming jerky. Usually, I just change the channel and go right back to the channel I was previously watching and it goes away. Also, from time to time, my remote will stop responding on the 811. The power button still works, so I end up turning the receiver off, and then back on. Then, I'm able to use the remote normally.
As far as HD, the 811 looks pretty awesome. Usually, I use the DVI output when viewing HD. It seems that component is close to DVI as far as picture quality, but component provides a brighter, more vibrant picture. I have had a few problems with HD channels becoming jerky. Usually, I just change the channel and go right back to the channel I was previously watching and it goes away. Also, from time to time, my remote will stop responding on the 811. The power button still works, so I end up turning the receiver off, and then back on. Then, I'm able to use the remote normally.