I agree, it's really disjointed. It spends a long time on relatively easy stuff and not much time on the hard things, IMO. I also have trouble with the style and I think it goes too far with the sort of informal, conversational tone. Ultimately Haskell is a language with a lot of formality at its core. You don't have to present it as all abstract category theory theorems and such, but that doesn't mean you should avoid formality entirely.