Recently re-read it after about 15 years. It retains its potency!
But I have one question, addressed to those who have also read the book. (And I'm trying to avoid spoilers out of consideration for those who haven't.) The fellow whom the devils were trying to ensnare -- did he marry the girl, or were they just engaged, or boyfriend/girlfriend? I could go back and re-read the relevant letters, but I don't feel like it. (I'm embarrassed by my faltering ability to retain even what I've just read!)
I'm under the impression that they were not married. Am I right, or did I miss some crucial phrase?