It's an action movie. I don't know anything about the books, and I haven't watched many zombie movies so I don't know how it should be rated in relation to the genre. Viewed from that perspective, in my opinion it was okay and worth seeing. It was packed with action.
I find the movie theatre over priced in general. $5 for a medium drink!? For fuck's sake. So I am saying it's worth seeing if you already want to go to the theatre. I like to go to the theatre a few times during the summer.