I really enjoyed it. I can live without the gore. To me it was like an action flick featuring zombies. I don't want to say a zombie movie doesn't need gore. When I think Dawn and Day of the Dead, I believe the gore adds significantly to those movies. Yet with World War Z, I don't believe the lack of gore is detrimental (besides our own love of blood and guts).
I can hardly remember the book, though after referencing my review of the book on this site, I am disappointed there were no underwater zombies in the movie.
The book and the movie are completely different. However, I enjoyed them both thoroughly.