This book starts out walking the reader through some of the basics of object oriented development. Right around Chapter 8 or 9, the primary author stops breaking things down as simply - with the result that anything that was missed in the earlier chapters (or was simply unknown) made it harder to proceed as effectively. It is written with the feel that this continues in this manner throughout the book.
Good examples, some degree of depth, and nice coverage of a variety of areas. I don't have a sense that this book is intended for one audience or one range of expertise - if you're a new programmer, this should not be your ONLY book, but if you're only new to ActionScript 3.0 or have never tried applying OO to scripting, this seems to be a powerful starter book. I believe the target audience is an I.T. professional who hasn't had a lot of scripting experience or perhaps limited recent coding experience.
I thought the book was great! Really has helped me in understanding application flow and basic OOP concepts. Definitely a book I would recommend to anyone interested in the Flash platform.