For what it's worth ... some time back I provided this high level feedback elsewhere. But to be honest you'll understand more MacKenzie on this site than anywhere.
Granted this book is smaller than either Bahto's or Klein's, but that's where the difference ends. This volume is just as strong as either of those two retrospectives.
I would say this book is very well balanced between MacKenzie's personal history, the background to what went into MacKenzie's work (i.e. what was involved), and aspects unique to MacKenzie course design. There are also select hole reviews, diagrams, green and course plans to supplement all this. The photos are excellent as well and complement the text well I feel. You really get to "see" what MacKenzie's about (especially the bunkers I feel).
This book resembles more Klein's "Discovering Donald Ross" in that it is not a "Confidential Guide" of sorts to MacKenzie's courses, eventhough Tom Doak is a heavy contributor to this book. It's also not as drawn out into the minutia details as Klein's book is. Doak's effort here gets more to the point of things without splitting hairs as much.
I enjoyed the passages covering Cypress Point, but for that you'd be better off getting a copy of Shakelford's Cypress Point. There's also a pretty good review of the Australian courses (especially Royal Melbourne). Of course, there's more (Augusta among others) but those two stood out for me. But these are all high level reviews and point out certain strengths only. So don't expect to know so much about "how" to play them. Different ballgame for that I'm afraid and you won't find the answers here.
Last but not least, there's a nice plan fold out of ... St.Andrews of course, where MacKenzie learned much about his craft and did much as well. You get to review the plan and appreciate MacKenzie even more. I'm glad this was placed at the end of this book.
Can't go wrong with this volume. Best I've seen out there about MacKenzie. Get this and MacKenzie's "The Spirit of St.Andrews" and "Golf Architecture" and you'll know your MacKenzie. After that, hit Pasatiempo or another MacKenzie gem and get to appreciate all your homework.