I might just warn you guys that there's probably some spoiler in this review so read at your own terms!!
I've been really crazy and hyped up about this sequel so I decided to bought the book and read it long before I watch the movie. Basically I know that it's impossible to put all of the scene on the book into the movie, and that's why maybe for those who haven't read the book yet feel a little bit confused and annoyed by how the plot feel so rushed at the end, how John character isn't really take a big part to the plot, and how could be Peter character feel more douchey than the first movie. Prolly it's all because they didn't put all of the characters development in this movie. God I swear they kinda left lots of the details and deep feelings towards the storyline and the characters. There are lots of explanation that didn't come up to the screen on why the characters did what they did, and so on. So if you not satisfied with the movie but still in love with the storyline I suggest you read the book. Also they didn't put lots of my favorite sweet-lovable-cute scene from the book into the screen, so.. :(
Still tho I love this movie, I love the chemistry between the actors, it so obvious that they were having fun shooting this film. Can't wait to see the third and the last movie!