Mostly spoiler-free review (very minor trivial spoilers).
Pros:
1. Casting. The casting seemed to be basically on point, as most Marvel movies are. Benedict Cumberbatch was good as Strange, Chiwetel Ejiofor was really good as Mordo. Setting aside the whitewashing controversy I think Tilda Swinton did a good job of adding a little depth to what would otherwise be a shallow Ancient One. Mads Mikkelsen did a good job with what he had to work with, although the villain is not as developed in this movie as he could have been (an oft-cited complaint about the Marvel movies in general).
2. The Magic. The portrayal of magic in Doctor Strange was interesting, visually arresting, and basically fun. I think there was a little too much shaky-cam to fully appreciate it at times, but I liked the fact that magic appeared to "bend the rules" in more than one way in the movie. There's magical melee combat, there's conjuring, there's astral projection, teleportation, dimensional travel, and reality warping. There's also the MCU's version of magical talismans which have touchstones to the comics but function to varying degrees in different ways in the MCU. The Eye of Agamotto is there, of course, as is the cloak of levitation. And the notion that magical talismans are imbued with not just power but personality is interesting.
3. The resolution. Without giving anything away, I liked the fact that Doctor Strange actually hews to something that happened often in the classic DS comics, which is that Strange is often interacting with forces so powerful that you can't just punch them until you win. Is there a climactic action set piece like most Marvel movies? Yes. Does Doctor Strange beat up the villain and win: game over? No. The ending is clever and appropriate for Doctor Strange and sets up what could be a recurring theme in future Doctor Strange movies: Strange confronts ludicrously powerful foes but doesn't have to become even more ludicrously powerful to beat them.
Cons:
1. Pacing. I felt the movie dragged in some places. Not enough to hurt my enjoyment of the movie, but enough to be noticeable. Particularly in the second act. In trying to show Strange's shift from ambivalence to proaction, I think the movie hung on the ambivalence too long.
2. The villain. As I mentioned previously Mads Mikkelsen does a good job with what he has to work with, but he isn't given enough to work with. I think there's a good villain in there, and he is presented as someone with an actual root motivation, but that motivation isn't expanded upon enough. Strangely (heh) the movie spends so much time on Strange's relationship with Palmer, his interactions with Wong and Mordo, and his early resistance to the Ancient One that it runs out of time to spend on the villain. Doubly interesting because it seems they all have a past: it is said (in the movie) that only broken people end up in Kamar-Taj, but that isn't expounded upon except of course for Strange himself.
Fridge Logic:
1. Why didn't Kaecillius approach Mordo to become a disciple? It appears like Kaecillius knew the one thing that would set Mordo off, and chose not to try. It doesn't seem likely that Kaecillius would not have known, given he was a disciple of the Ancient One for an apparently long enough period of time to get to know Mordo.
2. Could Marvel be setting up the MCU for a split, with the "cosmic" heroes in one section of the MCU - Doctor Strange, Thor, Captain Marvel, Guardians of the Galaxy - and the "earthbound" heroes in another section of the MCU - Iron Man, Spiderman, Black Panther, Ant Man, Captain America - with some heroes occasionally crossing over, like the Hulk? It is possible that post-Infinity War we could see a three-part Marvel Cinematic Universe: the Netflix universe, the (earthbound) Avengers universe, and the cosmic MCU. Which is kind of how the comics worked as well.
Overall:
8 out of 10. Well worth seeing. Further proof that Marvel can continue to expand its MCU universe while still keeping things fresh and not retreading prior movies.
PS: Sorcery is a melee set? Dang. Scrappers get all the good stuff.