Anyone who is a rabid enough fan of "Buffy the Vampire Slayer" to talk about it on the internet, is not going to learn anything from this Biography. 90% of the comments about the show by the writers, actors, and producers have already been stated numerous times in interviews and articles, and some of them have been stated better.
All the biography showed was a bias over-view of how the show was started, the movie (nothing that wasn't covered in the AMC Backstory a year earlier), and the extremely major plot points of every season. This would most like be interesting only to someone who missed out on the show during most of it's seven year run and wanted to learn about what has already happened and who the actors are. There was no talk of the controversal moments that went on in the show or behind the cameras, and nothing except the movie was shown in anything but good light.
I love the show, but this Biography was so bland and unneeded, I don't think it really needed to be made.