The Sci-Fi version is amazing for two simple reasons, the first is Ian McNeice as the the Baron Harkonnen (a role which McNeice absolutely KILLS as he's AMAZING AS HIM). The second is Children of Dune (which had never been adapted to film until the Sci-Fi channel did it). The actor who portrayed Leto the 2nd was pretty amazing and I only wish we had gotten a continuation of him as God Emperor Leto the 2nd of the Known Universe.
I tried watching two new Dune movies and I cannot for the life of me get into it due to the plot changes and more specifically the kid they got to play Paul. He has none of the confidence and passion that Kyle MacLachlan put into the role in Lynch's version. Also what in god's name did they do to Chani? Seriously, in part 2 she is seriously always angry with Paul (especially at the ending).
I mean, it really wasn't the same universe but rather a telling of how the universe BECAME Frank Herbert's universe (aka the universe during the Butlerian Jihad/Cymek War and the discovery of Arrakis and the Spice melange and also what it was capable of).
I'm pretty sure Leto was played by James MacAvoy, who played Professor X in the later X-Men movies. I just read a reference to that in an article about the new movies. Which I actually enjoyed a lot - I thought they were pretty on point for the most part, and visually stunning. Although I also did not particularly like Timothy Chalomet as Paul... I agree he lacked passion. To me it felt like he was kind of going through the motions, and I'm amazed at how many people love his performance.
The tone of Chani was deliberate according to what I understand from interviews with the director - he wasn't sure if they were going to get to do a third movie, which would be Dune Messiah, the book that kind of nails home the point that Herbert was trying to make about trusting a "messiah" to save you. Herbert was trying to deconstruct the kinds of stories that he saw being told where some prophetic figure would come along, everyone would rally around them, and they would lead humanity into a utopia. He thought that was a dangerous idea.
From what I've read, he was somewhat frustrated by the response to Dune and he wrote Dune Messiah as a response to that. He wanted to rub people's faces in the fact that Paul was a mass murderer who did what he did out of revenge, not from some kind of altruistic desire to "save the universe." And I think Denis Villaneuve gets that a lot better than Lynch ever did.
But since Villaneuve wasn't, and isn't, sure if he's going to make Dune Messiah, he wanted to get some of that into Dune 2, and Chani was his vehicle for that. She's the one who sees Paul for what he is - another nobleman, a wealthy privileged outsider, and a part of the system that oppresses the Fremen, who is willing to do anything to avenge his family's betrayal, and has decided not to care how many people are going to have to die along the way.
It's not Chani from the books, but in fairness, Chani in the books wasn't particularly well-fleshed-out - she was just some girl who was madly in love with Paul for no particular reason.
As for Herbert's son - I haven't read the books set in the past, the only one I even attempted was the sequel to Chapterhouse, and I got as far as Clone Leto magically turning into a sandworm before giving up. It just didn't feel like Dune. Since then I've occasionally read summaries of the subsequent books, or watched videos about them, but I can tell they're not for me.