I'm a Twilight fan, so I'm not sure how someone unenchanted would react to this film. But if you have a soft spot for the story, Breaking Dawn 2 is a pretty phenomenal conclusion to it.
Bella is good and vampiry, the humor is back, and the big showdown with the Volturi is a knockout. I was lucky enough to watch it with the perfect crowd: a Saturday afternoon matinee the first weekend, with a theater about half full. Nobody talked throughout, or lobbed jokes at the screen, but the audience reacted to all the big scenes with clapping, horrified gasps, and even outright shouting in complete unity. It was pretty cool. I hope the people involved in making the film have the chance to watch an ordinary audience seeing it for the first time.