I am currently reading the entire Night's Dawn
trilogy (actually 6 books, each in 2 parts) and I agree with the sentiments of all the other posters. The books are a lot of fun, and the technology is really very innovative and interesting. Two things about the series have annoyed me a bit however.
First, there is a gratuitous amount of sex. I'm by no means a prude and I don't mind sex scenes in novels, but in the first two books of the series it is non-stop, and in my mind detracts from the continuity of the story.
Second, these books are not a trilogy. They are one, very long (3700 page) novel. The individual books do not represent any sort of isolated story, if they ended a chapter earlier, or later, it wouldn't make any difference. You basically have to read the whole series. It reminds me a lot of a cliff hanger television show.