I have not read these since I was a teenager, back when they were released ("Lilith's Brood, formerly-known as the Xenogenesis trilogy, refers to a collection of three novels"). I cannot say how wonderful these were to me then, and I am surprised that now that I have re-read them in middle age (all 3 novels in 4 days! yes, they are still un-put-downable) how much these stories had become a part of me, a part of my imagination and how I parsed the world and fiction.
There are a few things that I noticed now as an adult that I had not noticed when young (no longer being a "subadult" myself, I get things more as a fully fledged grown up would, things that didn't overly interest me when young -- which is good. The novels are deep and textured). And there are a couple of historical tidbits in the first novel that momentarily make you realise what century this was written in (i.e., a Russia vs USA, cold war reference) but they are not integral to the storylines and they slip by very quickly. These novels are as easily read now, as a reflection on the human condition, as they were back then. They have not aged in that way and don't read like 'historical and good for you literature' but like great contemporary, engaging literature that you can't put down until you finish and when you finish you want more.
I am so happy I read them when I was young. I am thrilled that I read them again now. And I cannot wait until my own children are old enough to read them.