From The Atlantic online:
Exorcist 2 in my opine may not have the cheapo shock thrills of the first Exorcist or the unintentionally funny awkwardness of Blatty's Exorcist 3 (officially the real sequel), but it does have Burton spouting all that heavy theology, which on one side is irredeemable camp, on the other has Burton's beautiful growl and Boorman framing and lighting him in such a way he looks a hell of a lot holier (and more devastated) than Jim Cavaziel in Gibson's momumentally unimaginative Passion.
Then there's the filmmaking. Which is gorgeous. Which (some of it, anyway) is inspired by the flying sequences in Murnau's underrated Faust, only in gloriously amber color, as if Boorman smeared honey on all his lenses.
The film is a great something--sometimes I think a monumental sick joke on religion, sometimes I think a fantastic filmmaking experiment that you shouldn't (for the sake of your sanity) take too seriously. It's Boorman turning the theological bullshit Blatty (appropriate name, I think) spouted in the original picture into something that resembles science fiction--a scientifically workable theory on the nature of evil, no less.