If you haven't seen Snyder's Dawn of the Dead it's well worth a watch. It's a briskly paced ride that trades the social commentary of the Romero original for pure visceral fun.
That being said, if this movie is two and a half hours long (I don't know if it is, it doesn't have runtime on the IMDB page) that does not bode well. Something like this needs to get in, do it's thing and wrap it up before the audience has a chance to really think about what they're seeing (much the way a robbery crew does).