I wish every book would be written in the style the author has choosed. Every sentence reminds you that the author writes for a magazine and has a long time experience in entertaining and educating people. This fact has one drawback: as mentioned in another comment some of the materials in the book have been published before. They're not brand new but very well collected and combined together.
The contents have been proven to be very useful for me, a beginner in the field of patterns. The author told me in simple but not too small (no context) and powerful examples what patterns are about and how to find the pattern that suits my needs bests (using the GoF book). But the book is more than a reading help for the Design Pattterns book.
It also introduces a new - means not in the GoF book mentioned - pattern and gives insights to the discussion that have been hold when writing the Design Pattern book. The last one is not only nice to know but somehow helpful when seeking for new patterns in your daily designs.
One important thing to know when buying the book: all examples are written in C++. So please, don't be disappointed that features and limitations of C++ play a role when choosing patterns and discussing a pattern in detail.
Conclusion: easy to read, appealing for a pattern beginner, must have at least for a pattern beginner, good companion for the GoF book, expensive (it's just 150 pages).
