The book is only half written. Therefore, it’s too early to give a rating.
The clear statement on the state of each chapter is a great help and an idea I hope will be picked up by other authors. It improves the reading-experience massively.
So far, the book doesn’t meet my expectations. With this title I expect an extensive tutorial, yet all I can find is plenty of off-topic stories and not much of a tutorial. What should I do? Why should I do it this way? What alternatives exist? Why aren’t we following those? Answering those questions and explaining not only the how but the why could make this book a great help for people new to TDD. But for now this book isn’t there yet.