Yeah.. a few other folks have mentioned the line spacing issue. I made that choice because I wanted the book to feel "open" and "approachable". Not sure it was the right choice in the end, but it's the one I made.
As far as the drawings, I'm not sure what you mean by cloy?
Since I wrote this comment, I have continued reading the book, and indeed, I really dislike the line-spacing. It itself is distracting somehow. Of course maybe I'm fixated on it now, since I complained about it...
As far as the handdrawn graphics, I think it's kind of a schtick that XKCD created and it works for them, but I find it really tedious when others imitate it. The example chart, something about birds drawn on top of derivative symbols, didn't make much (any?) sense to me.
I appreciate that the book has brevity, and I want to motor through the text. I guess if typesetting is the main problem, that's a good thing. Probably among the easiest things to change.
As far as the drawings, I'm not sure what you mean by cloy?