I first read this book over 10 years ago. Even then I thought it was a little dated -- the author was clearly reacting against the Reagan era and extrapolating a hypothetical future where women have become chattel (albeit somewhat pampered chattel).
This is an "idea" book, and the ideas are fascinating. Laadan, the "women's tongue," (Elgin has actually created and published Laadan books), the power of communication, very alien aliens.. these are all interesting. If you are a linguist, a feminist, or someone who just likes far-out social speculation, this book will be interesting to you. It does have a certain hold on the imagination, such that I still remember it and think about it years later.
But as fiction, much less as science fiction, it leaves something to be desired. The entire premise, that the U.S. will become a sort of genteel Protestant patriarchal dictatorship, falls flat. (Some people may argue we are already heading in that direction, but I really can't see the repeal of the 19th Amendment and every man in the country becoming convinced that women have no more intellectual abilities than children.) Technology and space exploration is poorly explained, all the "sci-fi" bits are handwaved and thus there are some notable gaps in my suspension of disbelief. The aliens and the interstellar society exist as a backdrop for Elgin to explore her social views, which is fine if you are reading the book for social/feminist-linguistic theory, but will disappoint if you are reading the book for science fiction.
Most annoyingly, every single male character is one-dimensional. All the men are at best condescending egotists, at worst thugs. One is left with the impression that almost spontaneously, American society was taken over by a Protestant Taliban, and not one man ever questions the new social order. Aren't there ANY men who are not chauvinistic troglodytes, with egos so fragile that their world would fall apart if a woman ever demonstrated independence and competence in his presence? Not in this book, and not in many of Elgin's other books either.
I also agree with another reviewer; the first book in the Native Tongue trilogy is worth reading. The second book was mediocre and unfocused and didn't seem to come to any resolution. The third book, rather than picking up where the second book left off, did not tie up any of the loose ends from the first two books, and instead seems to be little more than a poorly edited collection of short stories that happen to be set in more or less the same universe.