Alright. When I was a teenage girl and later a young adult, I loved G.G. Kay's books. They were... emo, I guess. Made you "feel all the feelz". Strong women, dashing young men, teary-eyed tissue laden twisty plots. Beautiful.
Fast forward 16 years. I'm a grown-up, mother of two children. I've see a bit of life and I'm a lot less driven by hormones. And Kay's books feel different now. Forced. Too emo. Too contrived to target that tissue-spot. After the disaster that was Ysabel, and the meh Last Light of the Sun and Under Heaven, I was dreading reading this book.

Well. It was OK. I love the detailed picture he paints of China during the Jingkang incident. I didn't know much about the history of China, and he makes it alluring, just as it was with Under Heaven.
But almost the entire book contains too much background info. It reads like a long prologue. There is action, there is a heart-wrenching plot, but it is burried in pages and pages of worldbuilding and historical/cultural information.
The book could have been a third of its length and still have a (probably more) compelling story.
Also, the book is very plot-driven. Which is understandable, as it follows historical events. But the characters get barely fleshed out. It is hard to feel anything for anyone except the main character, Ren Daiyan. And that only at the dramatic end of the book.
The female lead, Lin Shan, started off interesting, though a bit too much like the other strong Kay women. From there, she disappeared. Her fire, gone. Yes, we get told over and over that she is unusual in her writing and poetry skills, and the walking around etc. But it just doesn't have a point. Even the fact that she captures the interest of the emperor is... rather unimportant. I just don't see the point of her character, except as a love interest.
The other characters are even more bland and 2 dimensional, even though it is interesting to see the events through the eyes of poets.

Why then the three stars?
The writing. If I had to sum up G.G. Kay's writing in one word, I would call it "elegant". Or maybe "poetic". Because he writes with beautiful use of language, smooth as silk and focussed on bringing on emotions. It is a silk with a razorblade hidden in it.
Reading his stories is like drinking a smooth Samos wine. Sweet, smooth, delicate, gently complex, and it will hit you in the head afterwards with a nasty kick in the gut.
I like that kick, even though it appears I have outgrown the teenage angst from the Fionavar Tapestry and Tigana.
Also, I like the twists in his books. The inevitable drama, that gets better on every reread. What happens near the end is one of those kicks and it is good. Small, compared to his early books, but good enough to be Kay.
Many people dislike what he did with the end of this book. I disagree, it is wonderful, perhaps one of the best things he could have done. We'll never know for sure what happened in the end. This jewel of an ending almost gets lost in the wordy mist of more historical information, but it is there.

I hope Kay will one day regain his skill in writing a compelling story with a twist, where action won't be bogged down in poetry and infodump.