Ok, I saw the movie and liked it. I liked it enough to purchase and read the book. As much as I enjoyed the movie it did not do justice to the book. The book so much more in depth than the movie would have time for in its allotted time. It explains so much more about why things are the way they are and what exactly happened to District 13.
I would still definitely recommend the movie. The acting is fabulous. But I would suggest reading the book before you see it. It would make the movie so much better knowing the background of what was happening.