I was excited to read this mostly because I was told about the great twists, but I was loving it long before the first one.
Jemisin is so creative: from the writing to how she handles the themes, everything has a special touch to it. The plot is daring: not everything she includes would work from any author, but Jemisin knows how to handle certain topics and express themes of agency, freedom and discrimination in a way that is relevant to but not derivative of our world. While the characters are likable and certainly enjoyable to read about, I don't think to create lovable people was the focus as much as portraying realistically how their situation might shape (and break) them.
The world building is immersive and the world created easy to grasp but very distinct. I love the plot and the structure it is told in and can't wait to see how this can possible go on in the sequels.