Solid review Stephanie.
I think Pitt's character's family was from Philly, not Manhattan as you mentioned. Just an irrelevant technicality, but wanted to point it out all the same!
I saw it last night at MOA and was surprised that I liked it as much as I did. The book was outstanding, but I went into with an open mind knowing that it was not going to be anything like the book. If you can't do the same, I'd advise avoiding the movie. Take it for what it is.
The book's interview-based format weaves an engaging sociopolitical look following the zombie war, using some compelling ideas that would very likely happen were an outbreak of something to spread in the real world. That's what made it so good for me - the real world politics and issues and how they impact a devastating outbreak. Think Contagion (great movie, by the way), only with zombies and a bit more elaborate. You don't get that with this movie, and maybe that's a good thing.
There's some cliches, as expected for this genre, but all in all, I found it pretty entertaining.