As always, it is a Butler novel. Intimate, powerfully-written female characters. Straight forward, almost simple sentences. Not stupid or writing down to anyone, but natural. I like this book and most of her other books for the same reasons I like books like Gary Paulsen's Hatchet and Robert A Heinlein's Have Spacesuit Will Travel; all of their lists and straight-forwardness and hard science. Ocatvia Butler then mixes it with genuine humanity. Only, as ever with Butler she gives it to you on such an extreme that you feel more than a little uncomfortable peeking in. 
 A feeling of general unease permeates through this entire series. It shares themes with her older (excellent) Xenogenesis series, but where Lilith explored human breeding, submission, resistance, desire, evolution, and what it means to be really human with the Oankali in a way that was somehow, impossibly, optimistic for all of its misery, Anyanwu and Doro's long, intertwining story fills the reader with dread, both for Anyanwu and for humanity itself. 
 I think that despite the horrors of a post-apocolyptic earth and the possible end to humanity as we know it, in Xenogenesis there was a light at the end of the tunnel. Humanity had options, and, ultimately, when you stopped being able to relate so much to the human protagonists the Oankali's and Constructs' own "humanity" was brought to light. 
 Not so with Wild Seed and the Patternist series. Humanity is merely food or fodder for the characters in this series. And even for the main characters, gifted or cursed with mutations, bred or the breeders themselves, there was no escape. 
 On the other hand, what we do get with this book, ultimately this whole series, is a wildly imaginative look at some of the darkest elements of our very human past, a very X-Men-like present (if Magneto controlled all the mutants in the world with an Iron Fist and could dictate every aspect of their lives for his own gain), a post-apocalyptic alien invasion, and the end game result of what Doro was trying to achieve in Wild Seed. 
 Be warned, the first book makes a great stand-alone and things change wildly from book to book. If that doesn't interest you, just stick with Wild Seed.