The only new Dune books by Herebert & Anderson I would recommend are Paul of Dune & possibly Winds of Dune. The House trilogy are fairly ok.
With The Butlerian Jihad it may be of interest to the serious Dune reader to flesh out the early time line. Suffer through it for a few intersting and ok parts.
Overly violent, sensational. plodding, pedantic and way too long.
It gets worse for the next two books in this trilogy and also for Sisterhood of Dune which also exists on the pre-history timeline of the Dune universe.