I haven't read Beyond the Zone System so cannot comment on it but Way Beyond Monochrome is very comprehensive but quite technical. The quality of the pictures is also very good which is important in a book on Photography but seems often to be overlooked in a lot of photography books. I had a look at Amazon and hadn't realised that it is also produced in paperback and Kindle. In my opinion unless you are used to Kindle and can be sure of the quality of the pictures via Kindle I'd be inclined not to bother nor would I get the paperback. It is only slightly cheaper and the sheer size and weight of it means that I doubt if a paperback edition gives it enough structural strength to last. It is a book for a lifetime. a reference book in effect and not a read once or twice and never open again or give to a charity shop because you won't need it again.
So, for all these reasons I'd get the hardback version
pentaxuser
I hope that all the focus on technique of the book don't drive me mad : ) I mean, a lot of written works try to give you tips, sometime one book overlap or another one. I had lesson by my Master of printing, need to cover only the lack of the using the Kodak Printer Scale with an efficient way to expose. Of course, the tone and how to evaluate the contrast is another important part, but I don't want the book to be difficult like a volume of study for university. I did it 15 years ago
Anyway, I don't like the digital version (Kindle, pdf) I will go for the solid paperback, because I prefer to put note on it.
Thank you for your experience expressed.