First, I quite enjoyed the movie. However, I feel that it is a good movie, but not a great one. It manages to find a happy medium between the frenetic action of recent science fiction movies (such as J.J. Abrams' forays in Star Trek and Star Wars) and the pompous weight of earlier science fiction (2001, Star Trek: The Motion Picture). There is a great deal of time spent with massive ships flying or landing, but not a multitude of camera passes over every nook and cranny.
What surprised me the most was how much it borrowed from the (sadly, much maligned) 1984 film. Now, I'm a big fan of that film, so I was happy to see that many of the production choices seemed to be a deliberate move to emulate that movie over the book. For example, the stillsuits take the darker look from the movie rather than the camouflaged look from the book with nearly the same nose-pieces so that we could see the actors' faces. Similarly, the Emperor's shock troops are shown in space-trooper armor rather than the crisp military uniforms from the book (which the Atreides troops still kept--in warfare that includes personal shields, cloth is much preferred over bulky armor). However, I like the look even if our current idea of "futuristic" might not age well, especially since it was such a clear nod to the earlier film.
Indeed, many of the "beats" of this film followed the rhythm of its predecessor--almost down to the camera angles. While events stayed a bit closer to the book (if I remember correctly), this close following of the first movie is a clear statement from director Denis Villeneuve, "I can do it better." Honestly, he is right. However, he did have the two advantages of more impressive effects technology and double the run time--not to mention a phenomenal cast (but the first film had that too).
Villeneuve said that this film is made to be experienced in the theater, and I can certainly attest to that. There is no way that my home sound system can compete with the thrumming resonance which this movie provides. Whether from the massive ships or the colossal score, this movie's sound rivals the expansiveness of its cinematography. Sometimes, it was even too much. There were several points where the music was soaring, but the characters were whispering. In this sense, I look forward to seeing it at home so I can turn on the subtitles. Only because I have much of the original film memorized did I know what they were saying.
That leads me to my largest complaint: this movie almost requires an understanding of the novel or original film to follow exactly what is happening. The 1984 film dealt with much of the exposition with voice-overs from the characters' thoughts and the princess's narration. This film largely just skips the exposition and places the famous "thought" lines as whispers. My sons did not seem that confused, so I might be overly critical here, but I felt that the story could have been developed a bit more (and had fewer dream sequences).
All told, I enjoyed the movie and look forward to seeing it again, perhaps even in the theater. Thankfully, Warner Bros. has already announced that they have greenlit Part Two. Unfortunately, it will be a few years (at least) before we will see it, considering that they haven't even started full preproduction yet.