Yes, the 1984 version missed the mark. But, I have to consider the times and how poor CGI technology was then. I mean, it was at the level of Pacman. We are now "light years" away from that type of production.
I had the good fortune of reading the trilogy years before seeing the movie. In a way, the movie managed to capture the feel of the book and some of the Reverend Mothers' nuances. But the story couldn't possibly have been told in that movie. It was too short. Without having read the books first, the movie left one confused and incomplete. The same thing applied to LOTR. There was a version back in the 70s that sucked. It had to wait until the present to have been made and made well enough.
Now, it looks like another attempt at the Dune tale will materialize into a movie to be released in a few days! The question is, will the movie be a trilogy like LOTR or another "one-shot" condensed version?