The Karate Code isn't a book... More of a booklet. It contains 12 very short answers to "Why study karate?" by several of the "old masters" of karate. While there may be some nuggets of wisdom here, mostly they're things that karateka will have heard before.
For the price, I expected something more than this. It was a waste of money, IMO. Also, be warned that if you're buying the kindle version, the format is very annoying, as all the pages are basically gifs that are too small to read without zooming. Gets repetitive and annoying; a simple transcription of the text would have been better, though it would have taken the "book" from ~75 pages to less than 10.