Prelude to Dune: House Atreides/House Harkonnen - Brian Herbert & Kevin Anderson
This won't be a proper review as it's been a while since I read either of these books, but as I have no intention of reading them again this is the best you're going to get. They were pretty awful.
In fact, the first one can't have been too bad because I went out and bought the sequel. The plot was fairly weak - some Imperial court intrigues and a nefarious scheme to do away with young Leto - but it was very nice to be able to revisit Arrakis and to see the back-stories of Gurney, Duncan, the Baron and all the rest. Unfortunately, by the time I got to the second book, the pleasant feeling of nostalgia had worn off and I was forced to sit up and take notice of the plot (grimace) and the style (yikes!).
The original Dune series worked because (dodgy science notwithstanding) it was a well-conceived epic on a huge scale, with broad themes of power, religion, eugenics, addiction... realistically, the prequels were never going to fit into that story because it hadn't started yet; all we'd have would be the Bene Gesserit mucking about with bloodlines, the Baron generally being evil and all the other characters growing up in their various ways. This presumably not being enough material for an entire book, Herbert and Anderson have been forced to cobble together some dodgy plots about a Tleilaxu invasion of Ix, Harkonnen family politics and some other nonsense that I've forgotten, probably hoping that the Dune franchise would be powerful enough to sell these books despite the pitifully weak content.
OK, yes, these are fiction books, and therefore made up. And, indeed, they are science fiction books, which means the worlds and the settings are made up too. But really, do they have to look so made up? I sat through the whole of House Harkonnen with a puzzled expression on my face and phrases like "What? Why would he do that? That's not right! You're making this up!" going through my head. None of the events seem likely; none of the characters act in believable ways. Clumsy, clumsy and bad. If you want to read about sandworms and Reverend Mothers, re-read the original series; boycott this dross like the swill that it is.