No doubt, this book is great, there are no others like it as far as I am aware. Its informative and well written and takes you through the history of bitters to actual production in good detail, and the book its self is lovely. There are many bitters recipes and also cocktails recipes to try them in (although it would have been nice to see more cocktails using the actual bitters from the book) and also a guide on tools needed for not only producing bitters but for bar tending. BTP has even added a section on recommend uses for bitters in the kitchen, which is a nice, versatile touch.
What would have been nice and perhaps this will come in a revision, would be alternative methods to making bitters. All the recipes in this book are made in a traditional fashion. They take a minimum of 3 weeks. A section on sous vide bitters would be an excellent addition as these can be made in under 1 hour with superb results.
All in all though this book is great, I would recommend this to any new or experienced bartender or chef, or just to the enthusiast.