My only crit is that the table of contents lacks info (it is great design-wise though). Could you add a second, more detailed table of contents at the end?
re: printed books - agreed! Especially since this is the third Vertex, we could put them on our shelves safe in the knowledges the 3 Vertices will form a tri. Naturally we will all be uncomfortable until Vertex 4 is released and we have a quad on our bookcase. Afterwards I'm afraid you'll have to change the name to Extrude…