I have just finished Doc Sidhe by Aaron Allston. It's quite an old story as the version I read was copyrighted in 1995. It's a story that has two related earths; the grim world (where we live) and the fair world, where its an alternative 1930's populated by the descendants of elves and other fair folk. The Doc Sidhe of the title is similar in a lot of respects to the Doc Savage character, apart from being a true blood elf.
While it's an enjoyable romp, there's very little substance to it. The story is told from the perspective of Harris Greene. He is a professional kick boxer and gets caught up in events that take him to the fair world. This is one of the things I didn't enjoy so much about the book. Doc Sidhe is just one of the characters that Greene runs into. OK, so Doc is the very rich team leader of a bunch of good guys who Green teams up with. But the story is about Green and is estranged girlfriend. The other characters have very little depth. This is also true for Doc Sidhe's arch enemy as very vague reasons are given as to why he has turned so evil.
Perhaps I was expecting a bit too much from this novel. It is an easy read and there are no despicable twists or puzzles for the reader to solve. I still don't understand why it received such rave reviews on the amazon.com web site though.