I was a bit disappointed with the final season, since it was mostly tying up loose ends and didn't really go anywhere new. But I still enjoyed the Christmas finale!
Yeah, I watched this last season on the UK timeline in the Fall. They definitely do wrap up most of the story lines. I won't say much else, not a spoiler. I will say that it's such a beautiful production and I love the historical detail. Even when the plot would get a bit tepid, it was still a lovely show to watch.
I wouldn't mind a Downton movie of some sort which has been discussed.