I really enjoyed this. It was a great take on a giant monster movie, and the thread of the character stories that tied it together added a compelling human side to the whole thing.
I can see why people found parts of it implausible, but overall it seemed to me like these elements were necessary to the story. The tale of the people who just evacuate to safety right at the beginning is not interesting, even if these people's attempt to save someone else in the disaster zone is absolutely crazy.
Also, I'm glad I saw it on video. I think the constant motion of the camera would have been terrible at the cinema.