I have not read the book, but I thoroughly enjoyed the movie. It had a cohesive storyline and things fit very well from scene to scene.
My wife did read the book first, and she enjoyed both. The movie obviously deviated from the book, but that really can't be helped (I tell people all the time - what works in a book does not always work on the big screen, so changes are needed).
My wife says you really need to read the book, which is far more immersing, and leaves a better chance for follow up stories.
`Le