there's a huge thread that's been going on in the "hot deals" forum here about the hauppauge wintv-d. is that the one you're thinking of buying? i know they have another model that does hdtv too (i think)
anyway, i was one of the luck ones to snatch these 300 dollar cards up for 50 bucks from jandr.com...unfortunately, they don't stock them anymore, but sounds like your still getting a deal, which is cool
go look for that thread in the hot deals forum, that should tell you all yo want to know about hdtv and hauppauge cards...overall, i'd say the reviews have been quite postive, the only factor being that you have to be relatively close to some HDTV transmitters to stand a chance of getting anything!