So I have now read every book by "Exurb1a", or every one that's on Kindle anyway, and I now feel confident saying "Geometry for Ocelots" was the only one I'd recommend to anybody else. "Geometry for Ocelots" was really really good though.
The others had good bits but also had problems, and I'm not sure in the end that I'm glad I read them or not.
@mcc Ah. I will read that book at some point. I generally tend to separate art from artist anyway, so even if those allegations are true, it will probably just mean that I get the books via other means that don't give money to the author, like buying a used paperback copy.
@mathlover Literally all I know is Kindle recommended me some books and I read them.