Almost more than the Sleepless themselves, a lot of what I remember about the book (and to a lesser degree the rest of the series — I know I read them all but I don't remember much about them beyond the first one, which I guess I must have read a couple of times) is the divide, not between the Sleepless and the sleepers but between the "genemods" and the non-genemods. There basically developed this underclass of unattractive, not especially intelligent, ordinary people who couldn't afford genemods, and of course the people who could afford them could literally buy for their progeny smarts, beauty, height, good health, etc. It was scary, and it doesn't seem all that far-fetched (I mean, the upper class can practically do that now, without genetic modification). I think in the books the "sleepless" genemod was outlawed fairly quickly, but the other ones weren't.

I did think the idea that it turns out that sleeping is a caveman leftover and that getting rid of it makes you smarter and never-aging was a bit convenient, but I bought it because it was the big leap the rest of the book required, and beyond that I thought she did a pretty realistic job.

I also liked her book [i]Brainrose[/i], in which a bunch of people undergo surgery to allow them to remember their past lives.

The whole idea of genetic modification is pretty cool, and Nancy Kress does it well, but what she does better than most science fiction writers, imo of course, is her characters. They all feel like real, complex, multi-dimensional people, and they're really the focus of the story.

I can understand people being disappointed at where the story ends up in the rest of the trilogy. The original idea gets lost along the way, if the original idea is the idea of the Sleepless. After rereading the series several times, I really think the overall theme is what do the powerful owe to the powerless? If looked at that way, instead of losing the original theme, each book builds and expands upon it.

But the original twenty-one were done when the Sleepless modification was still experimental – so it was offered to anyone with the money and the willingness to subject their kid to something that might go horribly wrong. As a result, not all the parents were capable of hiring a fleet of nurses to care for the kid – so, unfortunately, only twenty of the kids grew up; the twenty-first was shaken to death by its mother, because it wouldn't stop crying (I think it was implied that the baby in question was suffering from colic).

I don't remember how Kress handwaved the effects of sleep deprivation, but however it worked, it also resulted in the Sleepless not aging; their bodies kept regenerating new cells for all their organs (although they still went through menopause – the effect only worked on cells that were encoded to make more of themselves; eggs aren't encoded to do that).

As a note to the horrified mothers, though: as I remember, only the incredibly rich could afford to have the gene modification for their children to be Sleepless. They were the kind who could afford round-the-clock nannies and who wouldn't be dealing directly with their children all day (and night).