I really enjoyed it and thought it was more than worth the money. Admittingly though, I geek out over D&D history and am fascinated in the origin of the mechanics.
Besides getting to meet everyone that played in Arneson's games and watching those games slowly evolve into the first D&D like session, it also really drove home how personal the idea of D&D would have been to Arneson and gave some justification to the resentment of Gygax "taking it over".