Brian Herbert, with Kevin J. Anderson, took up the Dune universe's story after his father, Frank Herbert, passed away. I thought he did a very good job in staying true to his father's vision, and really enjoyed the two books of his that I read ("House Atreides" and "House Harkonnen").
I am very interested to read "The Children of Hurin" by Christopher Tolkien (son of J.R.R. Tolkien), which is coming out next month. Just like Brian Herbert, Christopher Tolkien used his father's extensive notes to complete a work in progress that was never finished.
One of the major themes of the worlds of these books are the legacies that previous generations hand off to future generations. It is fitting that the sons of two great authors, Tolkien and Herbert, have finished the work that their fathers had started.