I thought the quality of the HD feeds of ESPN-HD were great. I watched the Houston/Golden State NBA game on Friday and I was really impressed. It almost hurt to watch the highlights from other games because they were so grainy. Anything that is not HD looks about the same as normal ESPN, since they upconvert it. I'm looking forward to the start of the baseball/football season in HD and when they start Sportscenter in HD in the next month or two.
Discovery-HD looks great too. My wife and I have been watching a lot of shows on there this past weekend.
Installation was a little bit of a mess. The cable guy showed up with a non-HD box to replace my old box. I told him that I needed the HD box and it should come with component outs. With a blank look on his face, he asked what component outs were. So I explained it to him and told him that I needed the HD box. He called some of the other cable guys and they told him to go get one from the warehouse.
An hour later, he shows up with the HD box and starts to install the box. First, he hooks up the component cables and then hooks up the cable in. Next, since he had a hard time seeing where the rest of the cables go, he spun the box around, causing the coax cable to be pulled from the box and leaving the cable end on the box. At this point I decided that I wouldn't let him hook up any more of my cables and I quickly hooked everything else up while he was getting a new end for the cable from his truck.
When he got back, he hooked up the cable and turned on the box. At this point, we could get TV through the ReplayTV, but not through the component outs. So I went through the settings menu trying to find an option to turn on the component outs. When I didn't find anything in the menu, I decided to see if the cable guy put the cables in the right spot. He did, but he didn't push them in far enough. As soon as I pushed them in, everything worked great.
In conclusion, follow wvudrj's advice and don't let them install it by themselves. The cable guy said that he had never installed a HD cable box or seen any of the HT equipment that I have. If they would give the HD box out at the store in the Charleston Town Center mall, I could have installed the box in under a minute. Instead, I waited around all day for the cable guy to show up and then had to deal with a mess.