Slight spoilers for Dune Part Two and Messiah. I doubt it would hurt anyone, but better safe...
Children of Dune honestly put me off so bad I couldn't read anymore Dune. Messiah is a much more fitting end for the movies, since that's where most of the original ideas as well as Paul & Chani's story come to an end, although the climax of the book wasn't nearly as epic as the first; something that can be fixed with a movie adaption, and the ending of Dune Part Two seems like it's deliberately setting up for it.
The early ideas in Children of Dune honestly had me hooked for a while and I was racing through it like the previous books, but once I got to the second half it became a nightmare of philosophical monologue tedium, pointless setups that lead to no real payoff and some real over-the-top, character-destroying whackiness. The reviews for God Emperor of Dune said it's basically all the shit I hated from Children of Dune multiplied, that's when I knew I was done. Frank Herbert had a good run but someone should've really told him when to lay off the spice.
