I have read through most of this book. In fact my first software architecture book was the third edition of this book. I had the pleasure of meeting some of the authors and attending training sessions and workshops held by them at various events over a few years. The book is an excellent resource for software architects especially those working on large complex systems where quality is important. It also makes a superb textbook for undergraduate of postgraduate software architecture courses.
It is a technology agnostic resource (which is something I welcome) and gives a really broad yet deep view of software architecture fundamentals, quality attributes, architecturally significant requirements and tools for understanding, identifying and prioritising them. The book does one superb thing for a person like me who really likes systematic ways of thinking about work to be done. It exposes you to well defined tested and proven methods, tools and strategies for architecture analysis and design, documentation and evaluation.
A bonus is that each chapter has a summary, and most have great questions for discussion and further analysis as well as additional reading. The authors are not only analytical and academically rigorous in their treatment of the topic but provide many practical examples and case studies based on their own experiences. It is a great read and for me a handy reference to keep nearby.