What I Liked: Taming the Tongue provides a helpful overview of Scripture on the topics of edifying and destructive speech, and sections of the book covered aspects that I haven't heard taught as often or directly (the "Slapping with a Smile" chapter on negative humor particularly stood out for these reasons). I read this book as part of a group study, and each chapter prompted engaging discussions, which I think is another mark of its effectiveness.
What I Didn't Like As Much: During several chapters, I wish there had been more depth, since it did come across more as an overview to me. For readers with prior knowledge, the book treads familiar ground, but I think it had opportunities to dig into some of the newer areas more. For instance, I appreciated that Kinzer acknowledged that a hastiness or reluctance to speak isn't always a matter of willpower but can be tied to other areas of one's life, but the chapter stops short of exploring that idea other than to say that those areas should be confronted. This isn't a bad book by any means; I was just left wanting more detailed, practical discussions.