My wife and I watched it last week and I wouldn't say that it was as good as I had hoped.Haven't read the book so cant tell you how it compares. I felt it was a little depressing at times but with the story behind it that was understandable.
I saw the movie last week, as well. I haven't read the book, yet (on order through abebooks.com). The basic story line of the protagonist is depressing in its own right and really not a reflection on van life. I must say, for me, this was the kind of movie that changes you. Rare these days.