I read this book in about two days it is such a page-turner. It is no masterpiece but if you enjoy zombies stories (and i enjoyed "the Walking Dead"), you can only be happy with this opus.
more tha a novel, it is a fictionnal documentary, where the author imagines a series of interviews with survivors of the zombie war. This point of view gives the book the built of short-stories collection, since each interview, a few pages long, tells us about an anecdote, a differnt point of view on the conflict. So yes, this breaks a bit the pace of the book and one can be slighlty frustrated by certain chapters but it allows the book to explore many aspects of this horrible situation and it does give this "one more page..." syndrom that will make you finish this book in the middle of the night :-)
Due to this journalistic work, you watch the conflict start and develop (all is chronological) in the whole world with numerous nationalities involved. All this is very well done and one must applaude the research work of the author, Max Brooks, which brings a lot of plausibility to his narration. You get to witness an awful lot of various situations: you even get to the International Space Station... :-)
A slight problem is that the author, in his attempts to cover different national behaviours, is going to lose himself in a silly use of semi-xenophobic clichés. The French are compared to rats... War Z is the world seen by an American with an American grid, and you feel it more and more as your ead. Still I even found this rather nice ...
So, i really enjoyed this book, which is not very violent, considering its subject matter and i will read it again in the future on a beach. One reason is that the best image of zombies offered by Brooks is the the hordes of zombies walking on the ocean floor to reach, months or years later, the golden sand beaches ... He he, pretty viscious isn't it ? :-)