Not so long ago, I was reading a forum discussion talking about how fantasy worlds never seem to progress past a medieval level of technology; and whether or not it's possible to write a technological fantasy world that is clearly not science fiction.
This book does it, with its plethora of faerie creatures - and our protagonist, a changeling - working in factories and dealing with magical/robotic creations.
The book is complex, with strikingly original ideas, and a carefully plotted structure that at first seems pointlessly rambling. As the spiraling theme of the story is revealed, the reader realizes that the plot has also been following that spiral theme.
It's well done; even impressive. The book probably deserved to win at least one of the several awards it was nominated for.
However, I didn't love it, emotionally. Even though it deftly slipped out of the 'it was all just a dream, or mental illness' thing that I had a suspicion it was sliding toward, for a while. I feel like I appreciated this book - it just didn't become one of my favorites.