I am thinking of getting HD but the thing I hated when I had HD on cable was when I had one tv set on a SD and one on a HD tv, the HD tv had a delay. Does Dish have a delay betweeen the SD and HD feed?
One transit of 22000 (-4000?) miles each way would be a fractional second delay but actually the signal may go up and down several times. Watch some news interviews and depending on where it takes place the reporter looks dumb longer than others, particularly with the Middle East, which might go to London first.
As for HD vs SD, there is more processing (including in your set) of the HD signal so expect it to be later. This might be observerable from set to set in the store. The same happens in TV sound vs direct to sound system.
-Ken