Cumberbatch was not my first choice for the role—I had a long list that included actors of all races and genders—but he's an excellent choice. He's not playing Sherlock Holmes, but he is playing a smart and arrogant man, which he does very well. And the fanboy in me thinks he looks perfect. (Emma especially appreciated the shaving scene.)
Swinton does a fine job, but I would've gone with Michelle Yeoh for the Ancient One.
Benedict Wong is great as Wong.
The cape of levitation nearly steals the movie.
Chiwetel Ejiofor, one of my favorite actors, has a nice character arc. As do most of the characters—almost everyone we meet is a bit different by the end of the movie.
If the trailers disappointed you a bit, as they did me, with no apparent Ditkoesque supernatural dimensions, be reassured.
The tone becomes lighter in the second half of the movie, which may indicate the work of the second team of writers. I would've minded that more if the funny bits hadn't worked, but they work very well.
Fanboy Will gives it 9 out of 10 stars. Film critic Will gives it 7.5. It is not a great movie, but it's a very good example of "If you like this sort of thing, you'll like this." And I do.