"If you have to read a book for a movie to be 'enjoyable', then it's not a good movie.
That said, having read the book... the movie was absolutely rotten.
Unfortunately, no matter how much bad press it received, it was going to be a hit, because people all too often don't trust reviews/opinions of friends.
It was a 2.5 hour trainwreck of a story. It reminded me of National Treasure (if you removed the entertaining, over the top action sequences).
It was bland.
For those that watched Arrested Development... This movie was Ann "Egg" Veal."