Lets put is this way...I have an HD FTA reciever that records both sattellite or OTA signals. When I record a movie from stttellite, the file size on the hard drive for a two hour movie is about 4 gigs (give or take). When I recorded the Letterman Show, the other night (1 hour) OTA from channel 4 in Buffalo...the file size was over 8 gigs.

OTA has much more data and is not compressed. Satellite's picture is fine, but it is still compressed. Cable, from what i have seen is even worse. In other words it is more difficult to see the difference between sat and OTA, but there is a noticible difference between cable and sat.