This is a topic I'd been very curious about for a while, so I thought I'd fill in others on my experience with it now that I've had a weekend to play with a Zenith HD receiver connected to a SD Sony Wega. First off, HD programming. So far I've seen the NCAA game on CBS, part of Smallville and Everwood on the WB, Dragnet on ABC, Disney's Atlantis on ABC (the listings didn't say it was HD, but it was widescreen with 5.1 audio), and some travel programs and HD demos on PBS. All of it looked very, very good. I would have liked to have a copy of the Atlantis DVD on hand to compare it to the broadcast, but my impression was that the picture on it was very close--if not equal to--DVD quality. The WB and ABC shows looked great. Again, no means of comparison since DVDs for those shows don't exist. However, on Tuesday I'm looking forward to comparing the 24 digital broadcast (non-HD, but supposed to be DVD resolution) to my first season 24 DVDs. Digital non-HD programming also looks nice, definitely better than any other type of TV broadcast I've seen (cable, satellite, or otherwise). All in all, I'd say an HD tuner is a great way to "upgrade" an existing TV without getting into the huge costs of actually buying a new monitor. (That said, now that I've seen what downconverted HDTV looks like, I really want an HD set!) $400 (what I paid for the Zenith) is kind of a lot to pay just to make my TV shows look and sound better (even a lot better), but I figure it'll be a useful thing to have around if I decide to spring for an HD set somewhere down the road, or when the networks stop broadcasting in SD and every SDTV needs one of these boxes to function.