Overall, I liked the movie. It felt like something was missing, but I'm not sure what, so that's not a very good criticism. Ha.
It had lots of tension, lots of emotional impact, lots of weird screaming vampire-zombies. Will Smith's character once again manages to be The Perfect Man. He hunts, farms, traps zombies, military officer, genius scientist, loves his dog as an extension of his dead wife and daughter. Somehow the dog had to be revealed as a girl (Sam is Samantha), as she was dying and becoming a zombie/vampire dog, in order to drive that point home.
Of course, I couldn't be fully emotionally "in the scene" at that point because of the crying 8 year old behind me. "He's dreaming, right? Its just a dream? Why did the puppy have to diiieee??!?!?!" I was tempted to turn around and tell her the truth: the doggie died because your parents are too stupid to read ratings, it is all their fault the doggie is dead."