I received an advance copy of this from Tim Johnson, who runs a website called the Martial Arts Lineage project (Tim, I know I owe you a review of that site, and I'll get there, I promise). This is a review primarily of the Kindle format, though I'll make some comments about other formats towards the end.
The book is a compilation of answers to the question, "What is the greatest lesson you've learned from the martial arts?" There's some value just in asking the question: I've known more than a few people who spend a lot of time training, and not time thinking about why they're training, or what they're getting out of it.
Johnson draws from a fairly diverse group of practitioners in answering this question, from relative beginners to well known names like Dr. Yang Jwing-Ming and Diane Lee Inosanto. Chinese martial arts practitioners seem to be heavily represented here--I don't know if that's a result of Johnson's greater number of connections in the Chinese martial arts, or of a personal bias on his part. It's not exclusively CMA folks, certainly, and most of the ideas are broad enough to apply to any martial art. There's some fairly interesting and thought-provoking content in some of these essays. I like the fact that there's a diverse range of experience represented here. Sometimes, getting a perspective from the beginner is just as valuable as the perspective from the master.
Unfortunately, while some of the essays are thought-provoking, others are just bad. For every one that made me think "that was interesting", there was another that made me switch to Editor/English teacher mode. Some of the essays are poorly written, off topic, or just not very insightful. Some barely answer the question being asked. Others are so short as to hardly qualify as essays--they seem more like quick emails fired off to answer the question before getting back to work on more serious business. Brevity may be the soul of wit, but if the most you can come up with after years of martial arts training is a single paragraph, I'd suggest you put some more thought into your writing.
Some of the fault lies with the essay writers, but some of it lies with apparent lack of an editorial process in producing this book. There is at least one essay that lacks proper capitalization, which is the sort of thing that Word's spelling and grammar check will catch, never mind a trained editor. The lack of editing is sloppy, and frankly, hurts the book as a whole.
The final issue, for the Kindle edition, is the price. While the book isn't awful, at 72 pages (and not very full pages, at that), there are simply more insightful books you can buy on Kindle for the same price or less.
However, the book wasn't really designed for the Kindle, and Tim admits this. Tim was kind enough to send me a PDF as well, and in that format, it's possible to see that the essays are each accompanied by some fairly robust artwork. The entire book is illustrated, and it appears that the illustrations are designed to compliment the essays.
I could see this being the kind of book an instructor would keep out in a dojo waiting room or observation area. It is eye-catching enough to get people's attention, and the content is short enough that someone could pick it up, find an interesting story or two, put it down, and feel like they got something out of it. For a private collection, I think there are other books that will give you more insight for the money, but again, as a coffee table book, it'd be okay. I'd get the hard copy, not the Kindle version, however.