I loved New Moon. With an increased budget, the special effects improved greatly from Twilight and reminded me of the third Harry Potter's effects. Since New Moon is an essential part of the saga, revealing Jacob's character, showing Bella's relationship with him and infatuation with Edward, and allowing Edward to demonstrate his willingness to self sacrifice, I was very happy to see the way it followed the book closely. It included all the intense, pivotal moments between Jacob and Bella, bringing to life the intimate relationship the two share in the novel. It also tied together nicely, using Bella's letters to Alice as a way to narrate the story and adding smooth transitions. I am very impressed with the way New Moon was made!
The movie was very good and very loyal to the book in quotes and sequence. The actors did a good job of becoming their characters and showing chemistry where appropriate. My only complaints are that some of the lines are cheesy, the special effects could improve, and the climax could have been built more believably. But somehow even the flaws work with the story and add to its charm. If you liked the book, you will like the movie, as long as you don't go into it expecting every little detail to be included. And if you haven't read the book, the movie is easy to follow and will show you a glimpse of another world, leaving you wanting to know more.