Upstairs Downstairs is good. DA is a copy but I think it's a little more well done. Better acting IMO. Both good shows, but DA is what's running and that's what people currently care about. I understand why you've been making a serious push for people to watch upstairs downstairs though.
It's not a "push", just a FYI to people who may be looking for something similar. I'd never even seen Upstairs Downstairs until a few months ago. I've never really been a Masterpiece Theatre watcher. I have some links saved to various similar shows on YT (which I've meant to watch, but have never gotten around to) which I'll post if anyone's interested.
FWIW the production values are indeed MUCH better on DA, but I think the acting is, on the whole, superior on the old UD -- they even have a few greats like Gordon Jackson (the dourly efficient butler -- he was in The Great Escape), Angela Baddeley (the old cook), and the IRL married couple of Pauline Collins (the randy maid -- some may know her from the film Shirley Valentine) and her husband John Alderton (the scheming chauffeur). Alderton is a special favorite of mine, superb at both drama and light comedy. Unfortunately he never worked in Hollywood, so he's not very well known in the US.