I liked this series a lot. Theme-wise, it's pretty similar to much of Octavia Butler's other work - what does it mean to be human? How do you build a community around yourself? etc. It's also very cohesive - it's very much one story told over three books, and none of them are duds. I think my favorite aspect of this series, as opposed to the Patternist series, or Earthseed, was how, by the end, the aliens seemed almost more human than the humans. They are certainly more aligned with many human ideals than the humans are - but at the same time, whenever you start to feel too comfortable with them there is a reminder that these beings are totally different from the rest of us. There's a lot to chew on here and I suspect that it will keep popping back into my awareness for a long time.