As for AI part I must say that even though this book is somewhat old, its still very good for people new to the world of AI (such as myself). Since I only have another Norvig's book (http://www.amazon.com/Artificial-Intelligence-Modern-Approach-Edition/dp/0137903952/ref=sr_1_3?ie=UTF8&qid=1359373092&sr=8-3&keywords=Norvig) to compare to I must say that this book takes a more practical approach, allowing one to understand ways in which implementation efficiency can be improved.
For CL part - the best CL introduction and real world usage book in my opinion. Yes, I've read PCL, yet still this book digs a lot deeper when it comes to optimization patterns for Common Lisp. Motivation for almost every design choice is clear (overcoming Prolog's drawbacks is one of my favorite parts).
Also this book offers a variety of exercises and some of those are quite a time-killers.
As for cons - some of the exercises are formulated a bit freely. And again, book is 20 years old, so some content is a bit outdated, especially techno-related.