This is the first how-to writing book I've read and as such, I can't compare it to anything. I'm about to start a creative writing course so wanted something inspiring and helpful before I started. Your Writing Coach caught my eye and I finished it within a day.
Your Writing Coach is essentially a short overview on almost everything the writer has to consider -- the techniques of writing, such as how to create and use plot, characters, setting and point-of-view, and the more general aspects of writing, like how to inspire yourself, how to find out what you want to write, how to get published, how to fit your writing time in your schedule, etc. I'm struggling to think of something it doesn't cover. It doesn't mention poetry and short stories very often, it is stronger in information about novels and scripts.
It's very focused on positivity, encouragement and aiding you with the emotional problems that make you want to give up the dream; after reading it, I felt as if I had the encouragement to just do it and start my writing career. It contains several useful exercises to both improve your technique and to inspire yourself into ideas and writing them down, shown by many examples both of Wolff's experience and work and of quotes and writings of bestselling authors. I have tried out some of these exercises and they alone are worth the price of the book. One thing that has to be said about this book is that Wolff genuinely seems to want to help and insire you.
However, it has its flaws. The drawback of covering nearly everything is that it tends to skim over nearly everything; it only really devotes a few pages to each individual topic and some chapters seem to consist mainly of examples which may not be useful. Another flaw is how it covers almost all forms of writing. Although this is good for the writer who doesn't know what they want to write or wants to dip into several forms, it can get too general. Because of the nature of the book, many examples can be fairly useless because they deal with a topic or form you have no interest in -- for example, I am interested in writing fantasy novels, so some of the topics that dealt mainly or purely with scriptwriting or focused on particular fiction topics like crime novels weren't too helpful. That said, they can be applied to your own interests.
It is a good, handy, well-organised book that covers a remarkable amount of topics, but it can be too generalised and basic at times. It would be a good addition to most writers, but it may not be what you're looking for. If you're fairly knowledgable in the craft and practice of writing, its primary use may be just reinforcements and reminders of what you already know. If you're looking for a book that deals strictly with the nuts-and-bolts of actual writing, it may not be too useful, as it tends to skim over those aspects. If you're adamant that you want to write one particular genre in one particular form, you may want something more specific.
In essence; inspiring, useful and highly recommendable for a broad overview, but it may not quite be what you're looking for.