A frequent criticism of that book is that it is larger than it has to be, that the system is gratuitously complex and that the system takes a long time to use.
To be fair, I have not read that book, only the reviews on Amazon.
This book can be read in 1 - 2 afternoons. The system is simple, doesn't require special material, and only takes about 15 min a day:
Book Review: "How To Get Control Of Your Time And Your Life" by Alan Lakein