I'm just trying to wrap my head around this.
How many films are in your pantheon or on your list of best films?
And what was the last film that you considered a masterpiece?
First, have you seen this yet? If not, all of this is pointless.
Second, the last film I considered to be a masterpiece was Cabin in the Woods, for reasons completely different than this. Before that? Pan's Labyrinth. Before that? The entire Lord of the Rings trilogy, which I am convinced will be the greatest cinematic masterpiece of our time. It just succeeds on every level. (The Hobbit doesn't.) Also, LotR is the sole reason I'm in the business right now, so that is a bias I need to mention.
This movie will go down as an all time great, because it is groundbreaking. As Holy said, the script, ain't that great. It's the weakest part of the film. However, this movie has used a visual atmosphere in a way that I would say is unprecedented on screen. It will (hopefully) revolutionize the filmmaking process.
Also, anything groundbreaking is in my personal pantheon. Any film throughout history that was offered a new approach to cinematic storytelling, that has presented new ideas, that revolutionized the process, even if it was only through a technical nature. So there are quite a lot of films in what I would consider the pantheon of all time greats.
As for my personal best films, well now that's just objective. I wouldn't put Citizen Kane on my list, even though, (and I'm already sick of using this term) it would be in said pantheon.
And, honestly, I'm hardly alone in this sentiment. Go read through some of the multitude of overwhelmingly positive critic and fan reviews on RT and you'll see my thoughts repeated endlessly.
But, once again, this all matter very little if you haven't seen the film yet. Even if I were to sit down and tell you the entire plot of the movie in as much detail as possible, it would not even come close to experiencing the film on the screen.