I am buying and watching UK TV programs from the early seventies to the present day and at times when I look at the Amazon catalogue I worry that a program will be too dated. So far I have got away with it. I did worry that the latest one, Hazell, would show its age and not be enjoyable but that wasn't the case.
What does show is the further back you go the lower the budget. Some of them like the Sandbaggers and Strangers are almost stage plays with the sets they use. Another problem can be the print quality which can get pretty grainy. Today even a cheap show's budget allows good outside film location work. Once you accept these constraints on the earlier programs you can just sit back and enjoy the acting and story. I'm happy so far although showing off Nicholas Ball's backside in Hazell was a very seventies 'Get Carter' copy;-)
Mind you, I haven't built up enough confidence to go back to some of the sixties black and white material yet. I do remember 'Public Eye' and 'Callan' with fondness.