It's good in the sense that it answers some questions and brings an end to the series. However i don't think the storyline is that great, especially the ending like others have said here.
Also, i think she's trying to make the book darker and shows the stress and hoplessness of the main character, but i don't think her words are quite there yet. It still seem more suitable for children story book of more cheery type. May be just me..
Either way, still a great read, i finished it in 3 days and became sleep deprived haha