I'm a well read grad student who's bluntly honest about all things, although I try to be most honest about myself.
I had some issues, but I will get to those in a moment. They're not huge, and I really did enjoy this: it captured a lot of the redemptive arc Strange goes through, the humor and action.
There wasn't really anything that the movie didn't give you, but I enjoy novelizations. They refuse to put out adult novelizations for the Disney movies, so I'm stuck with the junior ones. Which I refuse to read until after the movie comes out as they end in the middle of the movie - because they come out before the movie does.
I like that there are photographs. I enjoyed how quick and easy this was to read. I even didn't really mind flipping between the past and present like the movie did, although it was far more present in the book. (I'm more interested in Strange after he learns about magic, too, so I didn't care as much about the past chapters. The strict past-present-past-present also made it seem more methodical than organic writing as the movie was more set in the present. I suspect this was just so the book didn't delve too far into the movie, but I still got irritated by this.)
The book also glossed over certain scenes, or ignored them completely. I suspect this was to not traumatize children, although I also suspect Disney is targeting a wide range - older children to adults - so I'm not sure why they keep targeting younger readers with direct tie-ins to things that might traumatize children. (Or I get it, it's all about money and securing said younger audience in the future, I guess I'm just not sure how well that sits with me.)