I picked up Exorcist: The Beginning today which, I think, officially completes my Exorcist collection. I have the 25th Anniversary edition of The Exorcist as well as The Exorcist: The Version You've Never Seen, I have Legion, Dominion: Prequel to the Exorcist and now, The Beginning (I also include Blatty's non-Exorcist film, The Ninth Configuration, in that list because of its continuation of thematic elements introduced in the first Friedkin directed film).
Even though I consider Dominion to be the Blatty approved prequel, I wanted The Beginning almost for academic reasons. The fact that they were both born of the same idea, share many cast and crew members, but are completely different films, is something that intrigues me. I also wanted to hear Renny Harlin talk about the making of his version in the audio commentary, so it was one of those things I always knew I'd pick up someday, and that day just happened to be today. I think Renny's version is worth $5.99.
Astute readers will probably notice that I did not include The Exorcist II: The Heretic in the list above. To be honest, I do not consider this to be a part of the series and have no desire to ever see it, even though I've heard that seeing James Earl Jones in a giant locust suit is worth the rental (see this review if you need something to back that decision up). I try to stick to the Blatty approved material and The Heretic was only approved insofar as Warner Bros. asked him for a sequel, he said he wasn't interested, they asked how much it would cost to do one themselves, he gave them a ridiculous number and they said SURE!
I wasn't even prepared to accept Dominion as canon until Blatty saw a screening of the film and thought it was pretty darned good, giving Schrader and his little film that wouldn't die the Exorcist thumbs up.
So, if anyone has any reasons why they think I should be giving The Heretic a try I'd love to hear them. Until then, however, I'll consider my Exorcist collection complete.