I read a lot of computer books, and normally they are about as exciting as watching paint dry. I can't claim this book is exciting, but it does everything it possibly can to ease the pain.
The author is obviously a professional writer, not a computer guy who knows stuff and is writing a book about it. The structure of the book is impeccable and extremely consistent. Each section has a description and then extremely well written walk throughs. This allows people with different learning styles to access the book differently. I'm a very experiential learner, so I might do the walk through first and then read about what I did, others may like to do it differently.
I have really enjoyed learning and growing in excel. At the time of reading this book I was progressively working on a real world spreadsheet. At the end of many chapters I would think "hey, what a cool feature, I could use it to improve my spreadsheet". As I spend a lot of time in this spreadsheet, this book has saved me lots of time by allowing me to streamline my work.
Curtis, write more books please - the computer world needs authors like you!