First I have to say that I din't read the books, and I don't want to do it because I don't want to be disappointed in the transposition on screen.
I think that the movie is really good. The chemistry between the actors keeps better and better. The love stories are boring sometimes but I understand that it's a pretty important thing at that age.
The only complain is that every new movie in the series is darker and darker: this one is almost just in black and grey scale.
I hope that the last two won't be just black screen and voices!