It's a complete and utter dissapointment. There is no compelling reason to use it whatsoever. I wish they would have never got our hopes up and announced/developed it, it's a horrible idea and horrible implementation.
No other vendor of DVR software for a PC requires an annual fee. No other vendors tie you down to using only 2 models of capture cards from one manufacturer. Other vendors are already supporting HD cards (such as Snapstream: http://www.snapstream.com/products/beyondtv/
) and directly allow burning to DVD, while Replay PC does not. It actually offers *less* features than a Replay TV hadrware DVR, most of us expect a PC based solution to have *more* features! It doesn't do Commercial Advance, IVS, or allow browsing/streaming from your other Replay TV's.
Almost everyone across the board aggrees, it's a stinking pile of dog do-do.