I'm using a Hauppauge 1250 which is half a 2250 (i.e. single tuner), and it works significantly better than:
* OTA tuner built in to Dish ViP622 DVR
* OTA tuner built in to Toshiba HD TV
Both of which are excellent products in every other aspect.
It's also a lot better than the cheapo USB stick I picked up a few years ago, but that's no surprise.
By the way, I get channels 55 miles away.