Inferior to the first book. The world building is top notch and the characterization is good, although there is less evolution of the characters than it appears at first. However, the whole series has been stretched out in an unforgivable way. While no scene is bad the whole is less than the sum of its parts.
It is no surprise that it has been adapted so successfully to TV, because it is in its heart a soap opera and it lacks the momentum towards a conclusion that say something like The Lord of the Rings has. Really it is everything that is good and bad about modern epic fantasy writ large. Has less to say about the human condition than you might think. Although. obviously has an interesting and very cynical view of power.