I have the book.
I'm not following the diet per sey, but I wanted it to learn more about the 4 nutrients important for diabetes: fiber, omega 3's, vitamin d and calcium. I feel the book is worth it for that information alone, and I am definitely incorporating all four into my eating.
After 10 years of mindless diets I've gone back to the only thing that worked for me, simply reducing calories. I'll be trying some of the recipes in the book, and there are some great tips in it. I'm pre-diabetic, so the info in this book was perfect for me. I think it's a really good book.