Pretty good with a few flaws.

Rating: 8/10 (9 December 2017)

Thankfully, I did not have my opinion of this movie tainted by the disgraced reputation of M. Night Shyamalan. I like the Sixth Sense, and despite the scorn people regard the Last Airbender with, I did enjoy it as an eleven-year-old seeing it in theaters. Split seemed pretty good from the trailers, and thankfully it was as good as I had hoped it would be. There were areas that it definitely could have improved in, but on the whole I liked it a lot more than I didn't. It was notable and good that the movie didn't feel like it had to fit itself to much into one genre or another, rather coexisting within a few genres.
There was good suspense and progression of gradually showing the audience the nature of Kevin's condition and what it meant for his three captives. Even though the premise is laid out pretty clearly in the trailer, there are a lot of important things that it didn't address about the way that Kevin's personalities interacted with each other. I was surprised when it was revealed that Kevin's personalities were fully aware that they all shared control of his body. The movie was also jarringly dark for a PG-13 movie, which I really liked.
The three teenage girls weren't exactly written in the most realistic or flattering way. Nothing they did made them seem overly dumb, but Claire and Marcia were unrealistically naïve in just about everything that they said and did after being captured. Fortunately, the audience gets a breath of fresh air with Casey, who, while she is not any more realistic of a character than her two companions, is at least an active character who is interesting to watch. Even though she wasn't that deep of a character, I thought it was sort of clever how Shyamalan allowed the audience to think that she was just weird at first and then gradually revealed the way that her past experiences were allowing her to deal with the situation she is stuck in.
The most noteworthy aspect of the movie of course is James McAvoy's performance. Yes, the role is clearly written to show off acting talent, but it was still impressive to see him go from one personality to another. It was sort of okay that each of the personalities were clichés in themselves because they all served a larger character. I would have been interested to see one or two more of these personalities make an appearance, but maybe that would have bogged things down a little. The whole theme of those who have suffered being superior to those who haven't wasn't as consistent as it probably should have, but it is somewhat interesting in itself. The movie at least lives by that theme in making Casey survive as a result of her suffering and Kevin making himself more powerful by channeling the pain that he has experienced.
Overall, I would recommend that most people see this. It's more of a thriller than anything else, but it can cater to people who favor many different genres. I was definitely entertained and engaged throughout the whole thing. There are some cheesy and annoying things about it, but I found there to be enough things to enjoy that I was able to forgive the annoyances. Overall Rating: 8.1/10.