...glad to see this post; it deserves its own niche.
"The Keep" is in my mind one of the best horror novels I've had the pleasure to read.
As for the movie...well, it's decent, but deviates far too much from the novel. Yes, it had action. Yes, it had some creepy scenes. Yes, there were some good actors in it. But there was far more atmosphere and creepiness left out than in. And deviation? Somehow, the confrontation at the end was like opening an empty jar of peanut butter: you could smell it but it did little to salve your hunger. Even FPW's delightful little bit about the Cthulhu Mythos (when "Molosar's" origin was being pondered) deserves mention.
I'd love seeing "The Keep" remade. If "done right", all the chickens can retire. No need to "do" 'em anymore.
Time for Mann to "man up" and let go.