Installers should be out here tomorrow to upgrade us to HD. They're bringing 2 HR20 and 1 receiver only model along with necessary hardware etc of course. So since I'll be new to it, I wonder if someone could give me some info/tips on it that might be useful. I'm currently using an R15 that seems to work ok cept the buffer and then I've used a 35 hr and a 75hr DirecTivo that I still use and LOVE. I've read here something about how the HR20 can stream music and movies and photos from a pc even if it's not something. I do have a question. I am trying Comcast HD and have had it for a week plus. I hate the guide interface cus it's too small, the R15 and Tivo are much nicer. I hate how ugly the Comcast UI is since it's totally stretched and not properly formatted or something. Sometimes when watching an HD program and then the pic will go to 4:3 mode if I bring up the guide or info etc from the Comcast, it looks much nicer formatted that way not blown up and stuff, the info or whatever comcast screen is up will then switch to full screen stretched type and look horrible. However the Comcast doesn't allow you to change this behavior. So I am curious how the HR20 does this and if there's anyway to make any screen changes in the Hr20 to help with colors or guide looks or anything. I'd really like the guide/UI to be HD and look nice without all the darn ugly jaggies. Is there any feature difference from hr20-100-700/hr21 the black one? I know HR20 is only one with on demand. Is there a way to connect an external drive to the HR20 to offload programs to it? Or over the LAN? Is there a way to tell the guide to only show HD content/programming? Like HD channels only and HD on demand only. Comcast does have that as an option that I like. It'll show only the HD channels in the guide, but there's like 10 only that are shown in that part. Can you search for HD programs like with Tivo? So you'll search and say find HD only.