I had the opportinuty to assist to a preview screening of Glass in Spain, which is where I am from.
It certainly is quite quaint to see what happens to Shyamalan's movies, which aren't generally well received at first, and it is after their release that they are reivindicated (Unbreakable, The Village, etc).
Glass is not going to be any different. To say that it is a good movie is to stay far too short. I think it is a true masterpiece, way ahead of its time, with a script that has so many elements going on that it is mandatory to see the movie at least twice to fully get the big picture. And the crazy thing is that it works like a clockwork. Yeah, of course it has a few conveniences here and there, but overall it is a really really good script.
And that is just one part of the equation. Let me begin to say that I think the Shyamalan from The Village is long gone, but, yet, there is such craftmanship in how and where he works the camera, there is such control of the atmosphere and its tone that turns watching the movie into a blissful experience.
What is more, McAvoy, Jackson and Paulson give stellar performances, Willis is also pretty good, but those other three are just magnificient.
I am not sure what the general audience's reactions are going to be, they may feel indifferent about it, or they may be dissapointed after the first 20-30 minutes, which is the most crowd pleasing part of the movie.
Just go and watch the movie, and rejoice. For once, we are not living in mediocre times.