It doesn't happen often that I give a book 5 stars. To be really fair, this book warrants 4.5, not 5, but because of GR's system, I will round it up to 5.

If you want to know what it means to have autism, read this book.

Moon has some experience with autism, through her son. It shows in this book. As an autistic (Asperger Syndrome, high functioning) woman myself, I found the main character Lou Arrendale, very relatable. His story is told through first person perspective, and his way of thinking and the impact of the world on his person, his well-being is very accurate for, I think, most autistic persons.
Autism in women is somewhat different from autism in men, but the core principles remain the same, and Moon managed to write a very true-ringing high functioning autistic person.

Aside from the wonderful viewpoint, it is a great book about a moral dilemma: if there were an (experimental) cure for autism, should people with autism be pressured into taking it? Is it wrong to have a cure, but choosing not to take it, when you have a disability?

This book is mostly a character-driven story. There is some plot, but aside from the moral question, it isn't really about the plot.
It is classified as sci-fi, because space and lightspeed/darkspeed is mentioned and in the end, Lou ends up in space, but I would rather call it "speculative fiction".

The end of the story causes the story to lose half a star. I feel a bit divided about it. As a person with autism, I naturally wanted the story to be: "Having autism is OK, and not taking the fix is OK because it is OK to accept who you are, disabled or not." And I wanted Lou not to take the fix and turn out to be OK. If I would have wanted him to take the cure, it would mean that I feel that I'm not OK, that I'm broken and need to be fixed, even if it may cost me my very self.
That was very difficult to read, and at first made me a bit angry with the book.
However, I can see that it works for the book. It wasn't a hasty decision. The morality of the question fills the entire book, and I think Elizabeth Moon deals very ethically with it. She covers the pro's and cons, and in the end, I do understand Lou's arguments to go through with it. For love.... yes, I would very probably make the same decision. But still, it make me very uncomfortable, even though I in my younger years I have often wished I could be cured.

Lou's wish to go to space is a bit strange. It doesn't really play an significant role in the rest of the book. Bringing it up in the last part of the book feels very contrived, as if she had to find a way to justify the sci-fi categorization.

Anyways, great book, really terrific yet fairly light, so go read!