I like the concept, but I'm not a fan of the execution. To be blunt, it comes off as very half-assed. The pages shown in the blog post look like first- or second-round drafts, not final revisions.

I'm sure this took a lot of work, and I applaud the authors for completing and publishing the book. However, in my experience, a product will always take a lot of work, but a good product will take a lot lot lot of work!