I also have a Terk TV55. It's good, but not great. Had to move it to the roof to get all my local digitals, and I'm only about 20 miles from the transmitters. The included amp helps.
I gotta say, though, Terk's customer service is pretty darn good. When I went to move the antenna to the roof, I realized I didn't have the correct mounting hardware anymore. One quick e-mail to Terk, and they shipped me the hardware at no charge. That was impressive.