I really liked Bitterblue! In fact, Bitterblue is my favorite in the series. 
 I loved seeing Bitterblue try to break the spell that her father had over Monsea, and how little she knew about her kingdom and then go on to learning more about it. I liked the connections to the other 2 books in the series; I also liked the new characters that were introduced. 
 I liked seeing bits and pieces of Leck's reign, and his hold on people. He is crazy evil, but I think Bitterblue will lead her kingdom well, and help them get past his reign of terror. 
 I think Bitterblue is an interesting character, and I understand her confusion about what's going on and her need to figure it out. She does have a sense of duty to her people and learns who she can and cannot trust. 
 It was a bit long for me, but it also wasn't a surprise, given the length of both Graceling and Fire. It also jumped around a little, and things felt very jumbled/mixed up. I get Bitterblue doesn't know what's going on, and so we learn and see things as she does, but at the same time, I think it could have been a little more clear. 
 Overall, I think it gets a 4 out of 5. I enjoyed it, and I liked the artwork throughout the book. But I also think it could have used some work. It's still a good addition to the series.