The ending sorely disappointed me. While reading Sandworms of Dune, I kept thinking back to the original Dune, and the tone and themes. Unfortunately, Brian Herbert and Kevin Anderson have strayed far from the thoughtful, philosophical, developed plotlines.
I read the prequels awhile ago. Without reading the prequels, the ending on its own makes absolutely no sense and is haphazardly put together. Reading the prequels, it is logical, but then, the prequels weren't written by Frank Herbert, and he barely referenced any of that material. It appears that Frank Herbert never left a true ending in any of his last notes and this is a slapdash of happy, perfect endings, when Herbert never wrote in that manner.
I do believe the Duncan Idaho would have had the role he did because he was prominently focused on through the Dune series. I never liked him, and never understood why he was constantly in the story when he seemed not to have a true role.
The relationships between the gholas and the time on the no-ship was drawn out. Hunters of Dune and Sandworms of Dune could be combined into one book. I didn't understand the purpose of bringing back all the gholas and neither did the writers of this book.
I have a hard time accepting that finality of this series is about robots and humans coexisting in peace. Where did that come from??? The ending was too easy, so simple.
Also, what was the purpose of the seaworms and how were they able to exist? This was never cleared up.