I really enjoyed Dune. I thought it did a fantastic job of hitting the more complicated aspects of the book without over-explaining every little thing. That was my biggest concern going in given that Frank Herbert's writing style takes you into the minds of everyone in the room at any given time. Not having a voiceover and still being able to relay the intentions/thoughts of the characters without them just blurting or going on long monologs was probably what I was most impressed with from a writing/acting standpoint.
The visuals and sound were incredible. On par with Interstellar as far as IMAX-worthy films. 90% of the time I leave IMAX theaters disappointed, but this is as good as it gets. Probably not a coincidence that space and the desert both lend themselves to scaling via wide shots, but Dune did a great job with it and making everything appear larger than life.
Minor Gripes:
At first I was little taken out of it by all of the comic book movie actors, but then I realized that if you nixed every current actor that has been in a comic book movie there would hardly be anyone left.
My only complaint, and it isn't really one, but the soundtrack constantly berated you with tribal scores and chants. I get what they were going for, and one or two would have been nice, but I just thought they over used it.
My final thought is that when your dad has a badass name like "Lato Atreidis", you've got to be pretty pissed that he just called you "Paul". I'm sure it's got some biblical undertone, but it still took me out of both the book and movie at times. I mean, come on Frank, you've got names that roll off the tongue like Leto Atreides, Vladamir Harkonnen, Duncan Idaho, Gurney Hallek, and then there is...Paul. Kills me.