I own this e-book and by way of a review I would say that given there is not a lot of information out there regarding how to build your own lenses its a good place to start with but after that it gets tedious with just build summary after build summary - the whole document is close to 1200 pages. There is little to no discussion on how to get the best out of the lens (by stopping down - even minimally) so the pics provided generally exhibit distractingly large amounts of aberration.

Also, while not specifically a problem with the book, LF lens makers should be aware that large format lenses are not discussed.

That being said, if you are looking to understand the basics of lenses and how to get one built and onto your camera its a good starting point, but it is certainly not the end all and be all of reference materials.