Can someone tell me how many GBs of drive space are available to me on a 622? Seems that Dish 'keeps' some for their own purposes? Its been a while since my 622 was empty of DVR events, but I think I recall it holding 30 hours of HD, and am trying to figure out how many GBs = that 30 hours? Also kinda curious if all HD programs on Dish take up the same amount of space, or are some more compressed than others? I recently bought a Seagate 750GB drive for cheap to back up my 80GB computer, hoping that Dish will eventually enable external storage, and i can start using it for DVRing instead.