Here's what Wikipedia says about digital terrestrial tv:
Then, from Elgato's website, there's this bullet:
Watch analog as well as digital TV on your Mac.
...so I'm assuming that's what you get for your extra $50 (which is also a 50% price increase.) Not a bad deal if you prefer paying out the extra bucks for digital tv. What I really like about analog tv is that (at least in metro areas) you can get quite a few of the major network channels for free, which keeps you covered for many of the current hit shows, football games, the Olympics, etc.