I concluded the long epic of a book series some weeks ago. Just the first six books originally written by Frank Herbert. Before I begin my long rant (diatribe or whatever you may want to call it), I can never help but compare all fantasy/sci-fi work with the GOAT of an LoTR. Both books have significant social commentary and are still relevant even now in spite of the years that have passed since they were first published. LoTR however inhabits a far more innocent world, still recovering from the World Wars, still making sense of what the new world order was. Somehow to me it was a more endearing and comforting setting.
Dune has this inherent sense of Doom, right from the word go (spoilers alert!) from Duke Leto who proceeds knowingly into a trap to two books later with Leto II who literally became the God Emperor doomed to millennia of loneliness (and of course his seeming corruption) not to mention our tragic (anti?) hero Paul Atreides and his beloved Chani in between. It has very relevant social commentary on dictatorship, how religious fanaticism leads to the extreme rot of society and how the oppressed and repressed can later turn into ruthless cults. The span of time it covers is impressive and its world building is completely immersive. Further you can keep drawing parallels to history as well as what you see happening around you. However, the decadence and sense of depression that emanates from the book can be a little overwhelming. The Honored Matres for instance are completely repulsive, in spite of a last-minute attempt to redeem them.
To its merit, it has some extremely strongly written women characters particularly the Bene Gesserit, to have their power even for a day! Lady Jessica and Darwi Odrade are among my favorites, and there are surely more.
More-over there is this over-arching theme on patterns - Frank Herbert is telling us that falling into patterns is near fatal, the Shai Hulud will come swallow you, society will go the dogs, you will become predictable and become easy prey to your enemies, so learn to do the unexpected. Then there is Duncan Idaho, who keeps coming back to life, a little altered every time perhaps, but with the same patterns and how he finally makes a break for it.
The other noticeable thing is the strong influence of Islam on the writing and the characters, especially in the earlier books. The Dune is clearly the Sahara, and a bit of Arabia and the Freemen are the tribes that inhabit that area. Did read somewhere that Lawerence of Arabia was definitely an influence (perhaps the character development for Paul Mau-dib Atreides). The names also have strong Arabic/Persian influence. And in the later books the Tleilax also seem to have some sort of an Islamic order with an aim to turn the universe into a sort of Caliphate.
The other influence is the books' own influence on Star Wars, apparently Frank Herbert always nursed the notion that George Lucas stole a lot from his work, but didn't really consider it worthwhile to pursue this further.
The Dune movies in themselves cover only the first book so far, leaving a lot out. They have expanded the role of Chani (possibly to give Zendaya something meaty :)) and condensed that of Lady Jessica. From what I've read they'll end the franchise with Dune Messiah, the second book.
Finally coming to the key ingredient of the book - spice, I wonder what it really was. Magic mushrooms cum oil, weed cum some magic star dust that propels rockets? This was the single most important currency in the Dune world. And so many times I couldn't help feeling Mr. Herbert was himself reeling under the after-effects of too much spice, maybe that's why some parts of the books took a little effort getting through! Well, if Lewis Carol could give us a wonderland with talking cakes and cats, why not him?