Personally, I found LYAH to be a great book. If there are places where the book is incorrect, I didn't have the background knowledge to notice. I felt the book did a good job explaining applicatives and monads by starting at the very basics and very slowly ramping up the complexity to a complete understanding. I know with many math books I have had a problem where some transformation morphs equation A into equation B and the reader is left wondering how exactly B was obtained. I never felt that way reading LYAH. I could see where somebody already knowledgeable with Haskell would find the micro steps overkill, but it went at the pacing I needed.