I have two of these, both mainly used on G4 Macs. They reduce the encoding time of an average movie from 14 hours (on my 1.2 Ghz iBook) to real time. I have also used them on my wife's (Intel) MacBook, which results in conversions done in a third of real time. The original software was rather flaky (maybe the reason for the negative comments above), but it was quickly patched to improve reliability and allow more control over the encoding process. It is possible to encode individual episodes from a DVD using the enclosed software. If you already have a fast Mac, it may not be worth the money, but if you have a G3 or G4, this is a great little item.