Before, during and after watching this movie I realize this movie was made with just one purpose - to entertain. No social messages, no character study. Just plain fun. Well, maybe not so plain, but sure as hell lots of fun.
I have not read the book; hence I am not in a position to judge how true the movie stays to the book - in look or in feel. Watching the movie in itself is such a wonderfully visceral and testosterone–fueled experience that it stands for itself apart from the book.