Oh, that's such a mood with being afraid to read the author's other books. I've had that experience with other authors, this sense of "how can the other books ever live up to this?", and indeed sometimes they cannot.

The fact that the book is so much inside Stevens' head would make this a fascinating book to adapt! I can imagine the story looking quite different when you have an outside view. (I expect that facilitated Miss Kenton falling in love with him: she's not in his head, so she can't see the rigidity there that makes the reader go "Hmm, maybe he's not great husband material, Miss Kenton...")