I love the movie! It was true to the book. When I read the book, it was hard to wait for the next book. Just like the movie...setting you up for the next movie. Hope it comes out soon.
In general the movie was suspenseful. It kept you at your seat so you don't want to miss what may come next. At times Keifer made me think of Jack Bauer from 24. If you don't over analyze the movie but enjoy it for a "horror & suspense" genre then you will enjoy it.