This is one of those books that is so iconic that my own opinion of it is more or less irrelevant. Still, I suppose it won't do any harm to review it here, so let's go.
If I recall correctly, I first read this book in 7th grade, which is now over thirty years ago. (You may be surprised if you watch my videos. I'm older than I look.) The main thing I remember from all that time ago was realizing, Oh, this is what politics is, that is, people maneuvering and jockeying for power, making alliances with people not because they liked them at all, but because they're useful in some fashion. I also remember liking it. I wouldn't say it was my favorite, but I did eventually read all six of the books by Frank Herbert.
So obviously part of the reason I reread this is because of the recent movies. I'm not sure if I would have reread it if it were only the movies, though. Another part of it is that I listened to an episode of Stefan Molyneux's show where he pretty much dumped on Dune for 45 minutes straight, which was amusing. So I also wanted to see if his criticisms held any weight.
So to compare it with the two recent movies: The first movie is actually fairly accurate. They cut some things for time, but that's expected. The feel and general story of the movie match fairly well, though.
The second movie, on the other hand, goes on a very different track, and mostly not a good one. The most obvious and indisputable change is the chronology. In the book, Paul Atreides and his mother are living among the Fremen for about 3 years by the conclusion. In the movie, it all takes place in less than a year. This, frankly, makes the Fremen look like children if they're willing to follow him that quickly. Also, there is no imaginable way to organize a planet-wide rebellion that quickly.
Second, the character of Chani from the books to the movie is unrecognizable. In the books, she does do some fighting (especially after being trained in the Atreides/Gesserit martial arts), but she is mostly a wife and mother. She loves and supports Paul. In the movie, she is a defiant girl-boss who is scowling something like 75% of the time. You could take the most attractive woman on earth and she would be unlikable after that treatment.
Regarding Mr. Molyneux, I must agree that the sandworms are difficult to understand. What could they possibly eat? While I'm reading the book, though, I can suspend that level of disbelief just fine for the sake of the story. Honestly, I think much of his dislike stems from his serious distrust of any kind of mysticism (with understandable reason).
My own overall opinion of the book itself? I enjoyed it. It's still worth reading, and if you haven't, I'd recommend giving it a try. If I recall correctly, the next two books are also good, but after that it kind of goes off the rails.
