I loved the original so I watched the new one half expecting to be disappointed. While I don't think it has reached the stabdard we remember from the '70s version I still feel it was quite good for an opending episode and I did enjoy it and will be watching again.
I have all the originals somewhere on video and, while everyone remembers the best and famous episodes, there were a few real duds you know! Especially in the first series.
I didn't really watch more than a few minutes of Downton so I can't compare but I suspect it may be just unfortunate timing that Downton came out and scooped the interest for this sort of period drama just a few weeks before Upstairs Downstairs.
I was actually very moved wathcing Rose wandering around 165 Eaton Place because of course she was the last one to leave.