I received my PHD6 yesterday morning. I am totally convinced that I made the right choice.
So far, I am viewing D* through S-video. I would say that this is quite good, certainly no worse than on my Proscan CRT. Larger screen size might make the crappy signal slightly more noticeable, but this would be true with any larger screen. I have been mostly using the "just" picture setting. The only time I really notice the stretched edges is when the camera pans and you get that warped picture look. I have not tried composite yet.
I do not have an HD STB yet, so I can't say anything about that. Was all set to go with the Zenith HDSAT-520, but after hearing about some of the problems I think I may wait for the next gen Sony/LG. (Can't wait to see Salma Hayek in HD!) I did get the DVI card in anticipation of using it for the new STB.
DVD via component feed is truly spectacular. It's hard to imagine that the ED version could have any better picture, as some here have claimed for the previous generation Pannys. I think that the brightness is greatly improved in the PHD6. This was one area noticeably lacking in the PHD5 (at least relative to the PWD5).
Absolutely no screendoor effect at my viewing distance. I can start to see it only at about 3 feet. I could definitely see it on the ED model at 7-8 feet, which bugged me a little. For myself, I was buying this monitor with a time frame of ten years. Hopefully, most, if not all, broadcast signals will be HD before then. The price difference between the PHD6 and PWD6 is significant (about 50%), but to me, it was worth it. Of course, everyone's financial situation is different, so it is a personal choice.
P.S. I got mine from Visual Apex. They are a forum sponsor with an excellent reputation. Check their website (link at the top of this page) for price.