I had pretty mixed feelings in the first chapter or so, but it grew on me. (Realizing that there was a glossary in the back definitely helped!) Before reading, all that I knew of Jemisin's writing was of her fantastic world-building skills, and she deserves the praise: I really got a feel for Gujaareh, and even secondary characters seemed very distinct.
The only warnings I'd give are some borderline disturbing/repulsive imagery, but otherwise I'd give it a PG-13 or so.
It took a while to get into it but the wait was worth it. The world Jemisin created is amazing! All the characters were well done and I ended up feeling for every single one. The writing style was also good. It was a much better written than The Hundred Thousand Kingdoms. She improved well over the time. Read it. The ending is gorgeous. Most things about this book are gorgeous actually.