I liked it, it was very goal oriented, breaking down particular things that trip people up, such as artificial sweeteners, carb creep, and hidden carbs.
It's full of tips that have worked for other people, she visited a lot of forums to augment her own experience, it's sort of a course on low carbing for weight loss.
Since it's so focused on weight loss, it might be less useful for someone moving into maintenance, but I enjoyed it and I think it's a book I will lend to friends often.