The book has a title which says 'patterns' and is a size, layout and style which is ideal for discussing generalized design patterns. It has very few code snippets, few concrete details and very few sections have even a single example. This would be okay if a little frustrating if the book were about design patterns; the absence of implementation detail could be explained as an attempt to avoid distraction from the general principles. The problem is that this is not a book about design patterns; it is a book about writing good code. As such the essay style of the book and lack of detail and examples is inappropriate to the subject covered and is the major factor in its failure to be value for money.
At its core this book says that code should be written to convey your intent to another programmers; not only the computer. If this is a new or novel idea to you then this book might be worth skimming through. Yet will need to read other books such as Clean Code: A Handbook of Agile Software Craftsmanship (Robert C. Martin)
to find practical advice on how to write good, clear, code. If you already know that good code is written to convey intent to other programmers then this book will be a great disappointment as it provides insufficient examples or practical details.