The film was okay but I have no trouble with Man of Steel outpacing it at the box office. It and Star Trek are both better movies.
I haven't read the book World War Z. Maybe I will at some point, but I'm not comparing the film to the book at all in my evaluation of it. The movie succeeded in entertaining me despite the fact that Brad Pitt's character couldn't have had less personality if he tried, and I felt that all the action sequences prior to the suspenseful sequences in the health organization (which, I gather, is where the reshoots start) were pretty generic and underwhelming. The zombies coming over the wall scene gave me flashbacks to Starship Troopers, a movie which did the same thing better 15 years ago.