I just finished a class where this book was the textbook. I really think that design patterns are important, but I don't think they're the end-all of software engineering (a misconception by some). My biggest beef with this book is just that it is out of date. I'd love to see UML diagrams from the GOF put in here, have updated non-software examples, and updated code examples. Also, this text dives a little deep for me - I need the practical. So, if you're new to DPs, try reading through Design Patterns for Dummies. It has less detail and better examples.