I was with GLASS for the first two acts. But the third act and climax are really, really bad. It's frustrating. You can feel it fall apart in seconds.
I don't like to do this kind of thing, but GLASS is a movie that begs to be examined in a "I would have done it THIS way" fan-fiction light. Lots of places where Shyamalan should have gone a different way. Predictable? Sure. But more satisfying. What a frustrating movie.