The Dune Universe is one I can slip back into any time and immediately feel at home. I have read the original six books by Frank Herbert three times, and most of the sequels (by his son Brian and Brian's co-author Kevn J. Anderson) twice. Between them, the stories cover thousands of years, but that makes no difference. I fit in anywhere.
And now, at last, having re-read Sisterhood of Dune, which introduces this particular trilogy, I have started on Mentats of Dune, and have on my desk, waiting (I love having a really special book sitting there waiting!) its sequel, Navigators of Dune.
A proper review of these two novels will follow all in good time.