Although lacking in details, this Washington Post article compares several HDTV Recording devices on the market. Some highlights:

• Comcast’s DVR has a clumsy interface, ads in their programming grid, and some quality issues.
• DirecTV’s HR10-250 built with Tivo has a better interface but cost more. They also complained that it was a little sluggish with noticeable pauses.
• Dish Player-DVR 921 doesn’t have the features of Tivo but has picture in picture while in the programming grid and a superior advertising fast forward.

The articly also mentioned the JVC HM-DH5U Digital VHS recorder which will record normal television or HDTV. This suffers the same VHS vs Tivo disadvantages, the tapes sound price ($15 - $25), and it doesn’t work with most set top boxes.