I had this workbook recommended by my therapist and went through it with him.
After the first 86 pages I already felt very relieved from a specter of personality traits that used to make life a rough time, the first 5 chapters being particularly of very big use.
The language is simple and accessible enough for anybody, information is well put up together and structured, making the book easy to read. The exercises are well combined with the information given and leads the reader to a proper way in implementing it practically.
Throughout the book I could not find it easy to implement such a large variety of techniques, sometimes feeling discouraged by the effort for completion and time required but that was just a manifestation of the perfectionism of the reader. There is no need to implement all the techniques at once and that's also the workbook's idea: to find your own particularized way through your struggles with these exercises. Also, the hardness of exercising proved to be a sign that neuroplasticity is involved and changes are made.
I gladly recommend this workbook to anyone struggling with perfectionism and not only. I personally found it very useful in dealing specially with my own anxiety, shame, guilt, stress and compulsiveness having their root mostly in perfectionism.