uPlay is a lot better than it used to be. The only major problem it has left is that it opens itself everytime you close a game, same as Origin. Origin has an option to turn that off but it doesn't actually work.
I've not had any issues with the uPlay client when playing The Division or the new South Park, they downloaded fine all the way through. I have noticed though that if you don't play a game for a while then it seems to disable the auto-update, so I found when I went back to The Division after a while, despite having had the uPlay client open to play/update other things, I had a big update outstanding for The Division.