Well, I'll confess I don't own all the books, just about 8 or 9 volumes from the version printed in the nineties. I'm glad there's an electronic version available that is more affordable.
That said, I do recall that I own the volume that contains Won-Hyo within it. Could you share what exactly makes General Choi's book so valuable other than the fact that his name is on it? My recollection from reading it so long ago are that the pages he devotes to forms are pretty dry with static posed pictures. Really no better than Mr. Cho's books if one were association-agnostic and one wanted to try to puzzle together a Chang Hon form.
I understand this is the authoritative source if you're an ITF guy, but...
A few examples. Note: I only could read the scanned page from the book posted on the facebook site.
1. Terminology and explanation of technique. If a stance has a name such as "Fixed Stance" in a pattern, you can go to the volume containing stances and get a detailed explanation of the technical parameters of that stance. Go anywhere in the world and people who are up to date will know the terminology and parameter. This book calls it a "Long L Stance" no apparent explanation of paramaters and differentiation from L Stance. Uses terminology not universaly known or described.
2. For any other technique, Stance, Kick, punch, or block, again, from the term in the pattern book you can access the technique in the appropriate volume and get all the parameters.
3. Each pattern is preceded with "New techniques for the pattern" and has illustrations of the techniques as well as addittional applications.
4. Each new technique for a patttern, as the pattern progresses has examples of applications. Some repeated from earlier patterns have examples as well. This facilitates learning distance, direction and method of execution, particularly with regard to previous or next positio
5. Foot diagrams show previous foot placment and new foot placement often with lines showing how the foot travels to get there.
6. FWIW IMNSHO the direction designation in both books while understandable could have been better if either compass or clock dial directions were used. However, General Choi's direction designation is universaly used.
7. General Choi's book is comprehensive. Some claim to have "All the Patterns" - 20 of them. Would you want a book that conmtained "All of the Alphabet" all 20 letters, or the entire english dictionarly, letters A-V?
Just off the top of my head