I was recently complaining to myself about some style and grammar issues (e.g. "Book" is redundant in the title of a book), but I realized I'm complaining about style and grammar issues of comprehensive documentation for a recently released programming language!
I respect the effort Rust and Steve have invested in documentation and hope their effort is replicated elsewhere.
Generally speaking, I would love complaints about style and grammar issues, to a point anyway. It's important to me that the informal / conversational tone remains, but generally speaking, I try to get the details right.
(We don't have 'book' in the title of the book, that's just the HN title.)
I really hope you reconsider your stance on the conversational tone, which made reading the book difficult at times. Being informal or conversational is not bad per se, but it leads to verbosity that obscures the content. Cutting out some of the current verbosity would make the book a lot clearer and easier to digest, and I think you can do this without sacrificing the friendliness and approachability of the book.
For you. I find good rhetorical writing easier to read and more likely to stick.