Overall I have to say 'wauw'. They pulled it off again didn't they? The MCU had quit some challenges when it comes to Marvel stories, I can imagine it can't be easy to sell a talking raccoon but they did it and with Doctor Strange his complex story line they did it again.
Stephen Strange is a serious and big character in the comic books so they had to make sure the movie wasn't a flop and they did a good job. A lot of stuff in the comics is quit hard to follow, the different universes, the time controlling etc. Yet they were able to bring it on screen naturally and I think it wasn't that hard to follow.
I liked the reference to the infinity stones. They revealed the time stone in the eye of Agamotto which is a little wink to those who are paying attention to the overall story line in the MCU films.
The fact that the ancient one dies at the end is something I didn't expect. I question if it was the right move since it's a big character to kill. It's perfectly possible to keep a powerful character alive without messing up the main character's story, watch what they did with Odin in the Thor franchise.
At last I wanted to point out that I really like that Mordo played a friend in this movie, the comic readers know that he will turn out to become Strange's arch enemy but they didn't rush it. At the end you kind off notice that he's not a big fan of the Ancient One no more but it's subtle which I think is a nice play.
