I didn't know of the Sweeney series until after watching Inspector Morse, but decided to pick up the pilot to see if I thought I'd enjoy the show. An emphatic yes! Even though this film "Regan" is over 30 years old, it is still fun to watch, even for a newbie like myself. Thaw is just wonderful (as always) and now I'm going to buy the series. It's too much fun to miss.
As someone earlier mentioned, it is much cheaper for those of us here in the states to buy an all region dvd player and then buy the dvds from Amazon-UK. Much cheaper and the dvds themselves seem to be more complete (the American version of Foyle's War for example leaves out a number of minutes of each episode for some unknown reason).
In any event, even if you are not familiar with this series, John Thaw offers his customary fine performance and it is well worth the price!