Dune good. Dune big.
I did walk out of the theater realizing while the movie really does nail the scale and scope of the book, it completely lacks the interiority. While told in the third person, the narration is still intimately tied to what a specific character is thinking and experiencing; it's part of why the book's such a psychedelic experience.
Example:
Doctor Yueh exemplifies this. While it comes across a little overdramatic in the book, he's depicted as incredibly ambivalent, torn between his desire to save his wife and the deal he's made to save her. You get some idea of how brutal and far-reaching the Harkonnens' grip is, some history of the Atreides family, and actual character motivation. In the movie, Yueh is just there in several different scenes, then steps out of the shadows once the betrayal happens, and just sort of goes "welp, it was me all along."
The idea of Paul as a messiah is glossed over as well; there's plenty of talk of him being "the one," but not much talk of who the one is. The Bene Gesserit conspiracy isn't really expressed, and Paul's existence as an ubermensch result of a generations-long eugenics experiment is conveniently omitted. This may be stuff for the sequel though, as realizing he's basically a plant might be a dramatic turn for his character. Though it might've helped to give him an arc in this movie.
It's entirely visually impressive, the design is really cool (though you could get the same effect staring at the Dopesmoker album cover), and it was cool to see an epic movie for grownups which doesn't hold your hand (though wasn't this supposed to be R? I got the impression the movie was cutting around violence), and hope maybe the sequel will attain more of the depth I was expecting.
well,
re "realizing he's basically a plant might be a dramatic turn for his character" is actually pretty explicit in the books -- in the first book initially and explicitly when he confronts the Reverend Mother during the final confrontation and more subtly when he finds himself in front of Count Fenring, who would have been a Kwisatz Haderach had it not been for being a genetic eunuch -- and in the later books (2nd or 3rd? I don't remember) when he goes off the golden path into the desert.