For better or worse, the book draws a fair amount from the DISC personality assessment. So in addition to thinking about my own teaching style and technique, this book helped me to think of myself as a student again and my own personality based on the DISC model. This was helpful in giving me a context for the tips & techniques the authors suggest.
Also, the book is extremely readable. It's not too lofty, so I could imagine any old schmoe picking up the book and giving it a go. The authors pepper the meaty book with many entertaining stories from their own classrooms. One chapter I found very helpful breaks down kids into age groups and grades and says, "Here's what you can probably expect from X age group." So not only does the book use personality to guide discipline, it takes age into account.
Many of the authors' concrete suggestions are given under the assumption that your kids program is run like a classroom. So, some of the tips might be tough to apply in, say, a large group setting, or in a discussion-based model like small groups. That said, there are some "guiding principles" along with Bible passages discussed throughout, as well as questions answered like, "Why do children misbehave in the first place?" which apply to any situation. So I found that for any shortcomings the book has in terms of relevance it makes up for in terms of helpfulness.
Throughout, the book provides xerox-able forms and even entire, scripted training seminars for readers to use. All fantastic resources! Though, I didn't always relate to the language used in these "scripts". I.e. giving teachers sweet and sour candies and asking how that experience is like disciplining kids. "Well, didn't taste good at first, but as I continued it got better." Duh. Sorry, I won't talk down to my teachers like they're preschoolers. That said, in the grand scheme this is not a big complaint, and nothing that can't be modified. There are moments like this throughout the book, but I have to imagine this is true of any discipline book - there's an abundance of suggestions and tips, so you take the ones that apply to you, and move on.
So, clearly lots of good things to be said on my part. While I can't imagine anyone who thinks they're doing well with classroom management would read this book, for newcomers or long-timers looking for some help I'd highly recommend it.