Carradice: Glad that you are enjoying
Children of Dune. You know, the second and third book were already in Frank Herbert's mind when he was writing
Dune. He wanted to portray the whole cycle of a messiah.
Years ago, read those two and was mildly disappointed. I wanted more of the original Dune, and they are something different. Later on, I re-read them with a fresh mind and without expectations. When you value them for what they are, instead of what they are not, they appear as very fine books.
I have this hope that, eventually, both
Dune Messiah and
Children of Dune woult be taken to the big screen by Denis Villeneuve. Hopefully the first two Dune movies (
Dune part I and II) do not disappoint. The trailer is magnificent so far, and the actors and all the people working in the project, top notch.
Jinxtah: Truth be told, I found the second and third somewhat disappointing, because I was expecting more of Dune, as you wrote. I'm determined to get through all the Dune books Frank wrote, but I hear they get progressively worse with every book. 2 and 3 are still dune, it's just that they're not... Dune. You know?
I can understand that perfectly. If eventually, when the dust has settled, you give them another chance, they might surprise you. The second and third books complete Herbert's original vision so well. However, as you mention, they do not give the same vibe. Dune is so many things. One of them is a coming-of-age tale and Paul's ascending path. While Dune Messiah shows Paul in his maturity. He knows enough as to understand that all his power reaches him only to choose between the bad and the worse. While the first book offered expectations, hope, revenge, the second only shows grim certainty and disillusion. Paul's achievements are to him like ashes in his mouth.
About the later books, God Emperor of Dune suffers of the effect that you noticed with Children of Dune. Maybe more, because, it happens thousands of years in the future. Yet there are connections. Still, it also improves when you read it without expectations. Basically, it explains some of the decisions of a certain character in of Children of Dune, as much as Children of Dune explains some of the decisions of another certain character in Dune Messiah. It is good when taken in its own terms (IMHO).
Then, there is further hope, with the fifth book, Heretics of Dune. This book is considered by many the second best of the saga, after the original Dune. Rather entertaining. Then, Chapterhouse: Dune is a decent sequel.
Since you already are working your way through Children of Dune, I would say that it is worth getting to the end. Maybe you will make your peace with Herbert for not writing a wonderful, amazing, timeless pageturner each time he got near a typewriter, but instead mixing masterpieces with very decent books.
If you ever want more Herbert, then The Godmakers deals with different aspects of the religious experience, and the ascent of another character. Entertaining, and while widely different, some regard it as a companion of sorts to Dune.
Also, The Jesus Incident, the sequel to Destination: Void, was the confessed inspiration for the setting of Sid Meier's Alpha Centauri. So, if you ever liked the game, there you have the source.