I just saw Dr. Strange yesterday as well, and yeah, it was incredible. It's definitely my favorite Marvel movie and maybe my all-time favorite movie. Here's what I liked about it:
1. The "magic" made sense. I think Dr. Strange has the most believable "magic" universe I've ever seen (previously I would have given the title to the Avatar the Last Airbender series), because it mostly works exactly like how you would expect it to. It's not like there's some long list of spells that can be cast by saying or thinking the right words and moving your wand in a particular way. You get the feeling that the laws of magic are built into the laws of nature in a simple and elegant way, even if no one (none of us and none of the people in that universe) really understands exactly how they work (just like how we think scientific laws are probably very simple even though we don't understand them fully yet). Magic is about bending the laws of nature, time, space, and consciousness. That being said, that was all stuff that I was expecting to get going into the movie, so there are a few things that didn't quite live up to my expectations. I didn't like slide rings serving the function of wands (you would think you would not need some special object to perform magic). I also didn't like the cloak, but I'll get into that more later.
As sort of a sub-point (this is very slightly spoiler-ish): I really liked the way time-based magic worked, because 1. there was a reason not to do it too much (because you didn't want to break the universe), and 2. it only applied to certain spatial regions where it was being directed, so you didn't feel like, hey, why is that guy going forward in time when everything else is being manipulated weirdly, or why is he maintaining his memories when he goes back in time, or whatever. It's very rare for movies or shows to do stuff with time in a way that I can still suspend my disbelief, so they did really well there.
2. The visuals are just absolutely incredible. I'm not sure what else to say about that, but I hope the brevity of this point doesn't downplay how emphatic I want to be about it.
3. The plot and characters are good, and there's stuff that happens within the context of that universe that keeps things unique and interesting.
4. Like most Marvel movies, they do a good job of integrating humor into a serious and exciting story. There are a few moments that are pretty funny.
Here are some things I didn't like about it:
1. The cloak serves as a deus ex machina throughout the movie. There are several points where he's just magically saved by the cloak. This is made worse by the fact that it goes completely unexplained. The movie is only 115 minutes, so I think they definitely could have afforded to spend some time talking about it. Mostly it seemed like the only things it really added to the movie were comic relief in a few places, and otherwise it seemed like it was just there because it was probably important in the comic books.
2. Sort of going off of that, the pacing felt a little off to me. It felt like they weren't really sure whether they wanted the movie to just introduce you to Dr. Strange and the other characters and backstory and universe, or if they wanted it to have a more standard save-the-world plot happening, and it felt like they didn't have enough time to fit both of those things together, which is odd, because again, it was only 115 minutes. I think it could have been better if they would have spent an extra 30 minutes or so going a little deeper into the backstory and explaining the universe (especially the cloak), so you could get a better sense of exactly why we care about all the things that are happening.
3. I thought it was a little unreasonable how quickly Dr. Strange went from being a complete newbie to superhero status, but I guess the timing was never really implied, so I justified it to myself by thinking, everything that the movie is showing us is taking place over months or years. Except then why did the villains take so long to accomplish things, so I don't know.
Overall a really fantastic and unique movie.