I am an Orthodox Dune fan. By this I mean that I feel that only Frank Hebert's original novels are true canon in the Dune universe.

1) The true vision of Herbert is described primarily in the first novel, Dune. Subsequent novels are dimmer echoes of its genius. Many academics feel that Dune should be considered a stand alone novel, or the Dune Trilogy.

2) Brian Herbert, and Kevin J. Anderson are doing irreparable harm to the series with their trite, penny a word, and unoriginal works. Part of the beauty of Dune is not fully understanding the schematics of how Mentats are trained, or how the No-Ships were created. The mystery, and mysticism of it all helps to define the series. Yet, BH, and KJA want to beat it over our heads with relentless details, stupid additions.

3) BH and KJA's works fail to do either one of two things. They could faithfully work only with Frank Herbert's notes, and reconstruct only when necessary. Or, they could create a world, with new creations, new ideas, and new potential to craft the Dune universe in all its fullness. Yet, they do neither. Their works describe a universe that is too far from Herbert, and too close to conservative temperaments that it fails. Herbert didn't feel the need to directly write scene to scene, switching PoVs every time something happened. It wasn't necessary. But, BH and KJA too, thus slowing down and mucking up the narrative.

4) Herbert was a gifted and brillant story teller, and without exception, Dune is his greatest achievement. Why? Dune is literally a novel written in poetry. Every sentence is wrought with sublime power, and soul stirring beauty. Literally, it is written as a holy book, to emphasise its religious and spiritual themes. The rest of the series is similar. However, in the prequels and sequels, the tone is exchanged for crap hard sci fi writing that fails to engage the reader.

5) There are few, albiet minor issues with the original Dune series. The prequels, and sequels are frought with errors, let alone when compared to Dune Encyclopedia, which only emphasizes their unofficially nature.

6) Part of the joy of Dune is the fact it is incomplete. It is a magna opus without an ending, because in the end any ending we could conceive would not be worthy of the series.