As a lifelong procrastinator on her way down the hill, I have read MANY books on this subject as I try to conquer my problem. This book is the best for me. Others who criticize the categorization may not realize that no one fits into one niche. Because I fit into three categories, I do the exercises for all of them. The visualization exercises are so powerful they bring me to tears! I don't understand why, as they are abstract, but my reaction tells me they are hitting the mark.
I have improved my productivity greatly by DOING the exercises in this book. For me, learning the causes behind my behavior helped me to make better use of my time, most days now! For the rest of them, I have learned to be more forgiving and not become frozen in the self-blame and guilt that contribute to the problem. Each day is not just another day to put things off, but another day to try again!