Just got back from watching it...Not giving away any plot info here...It's not the best Marvel film, but it's gonna be hard to beat "Days of the future past" or even Civil war.. but it certainly isn't a bad movie.. imo it's better than the two Thor movies and the last two iron man movies.
This is probably one marvel film I would highly recommend watching it in 3D... there is a LOT and I mean a LOT of cgi and effects work such that you will notice the 3D pretty much from the start of the film all the way to the end...
I don't know much about the character himself so I can't really comment if Cumberbatch meets fan's expectations of what Stephen Strange should be like, however to me he seemed believable as Dr Strange.. but I do know comic purist may not be happy that the Ancient One isn't Tibetian or Asian.
There is some humor in the film but not a huge amount... I think the CGI detracts a lot from the story and humor simply because there is SO MUCH CGI! perhaps too much as a result. One will need to bear in mind if you got dizzy watching Inception, expect the same here. There's a number of scenes that really do spin your perceptions around and around!
There are two post credit scenes as with most standard Marvel films, one right after the initial credit roll, and then one at the end of the credits. Definately stay to watch the last credit scene if you enjoyed the bulk of the movie, if not you can probably skip it and leave early.
Overall I would rate it a 7 out of 10 movie...