This is a good book for someone who is motivated. The exercises will definitely improve one's technique, while being musical as well. If you aren't good at reading bass clef, you will definitely improve that skill, too.
The doesn't teach technique however, so you'll need another source for that. But if you have the basics (e.g. you know how to hold the bass, and you are at least familiar with reading music), then these exercises will definitely help you develop your playing skill.
BTW, if you're comparing it to "Bass Fitness", the main thing that I'd say is that this book is much more MUSICAL. It covers a variety of styles and puts technique in context. For example, the exercises in this book cover 48 bars and include chord changes, while the other book has exercises that cover just 4 bars which are played with a high degree of repetition. This is not a criticism of the other book, but I think the comparison is obvious, and I think this book offers much more.
I wish I had this book 20 years ago.
Pedulla Club #136, VM Jaguar Club