This book is unusual, to put it mildly. It purports to be not only the first book on testing Object-Oriented Software, but also the first really Object-Oriented Book. While I find this a bit of a spurious claim, the book's testing methodology certainly seems object-oriented enough.
This is not a book to go to if you are looking for advice on how to test a class. Rather, it describes a software quality methodology for the entire project lifecycle - and one that needs buy-in from the whole project! As far as I can tell, it seems well thought out and sensible. The author certainly emphasises practical issues like the customer-led level of quality. It is certainly a useful addition to the standard methodologies, which tend to leave testing a little short-changed (though some are better than others are). My main points of criticism are that I found the book unnecessarily difficult to read and that the 'case studies' seem rather naive. But if you are embarking on a major software project, this book will be of help to you - if you are not afraid of a long and heavy read.