My parents have had sky for YEARS, starting from the first system that had the 2 boxes, 1 for the channels and 1 just to decode the signle from the dish. Never got a problem with it, now we have Sky+, record shows to watch them again etc. Picture quality is superb, it's like watching a DVD. You can also get Dolby Digital 5.1 on most programs and movies if you get Sky+
