Great book throughout, but the passage that describes the concept of "Dead Hands" completely changed my short game. His 3x4 thing is a little too rigid for me, but it is helpful. I tend to stick to my 60* when pitching the ball from inside 100, but I do know specific distances of my 7:30, 9:00, and 10:30 swings. I tend to adjust from there by choking up/down on the club, also just "feeling" a slightly longer/shorter backswing. The chapter on bunker play is also very good.
I used to always lay back on shorter par 4s and par 5s, trying to make sure I had a full swing to approach the green. While this was effective, and often resulted in pars, but I wasn't taking advantage of my length off the tee. I now have to confidence to bomb it up by the green, and have the ability to get it up and down for birdie.
I shudder to think where my short game would still be without this book.
(hint: I would still be constantly air-mailing greens from 75yrds!)