At time of writing I am on day 6 of 90 on this weight-loss journey. I will update this review following that to tell you how well it worked. Bear with me if that's what you want to know!
For me, this is a brilliant weight-loss system. The criticisms I've seen so far seem to be from people who didn't follow all the steps correctly or give themselves enough time to work with it. This is not a quick fix diet, something you can do for a week then go back to "eating normally", it's for people who need to change how they eat for good. Possibly they didn't have 'the right kind' of weight problem (I will explain what I mean about that in a bit!) I don't see how anyone can fail to lose weight if they genuinely follow all the steps - there are only 4!
Other criticisms I've seen are about the book being expensive, nothing new and 'just like any other diet book'. I agree that it could be cheaper (which is why I bought mine on ebay!) The version I have is the colour one from 2010 with the CD and DVD. As many of said, the CD and DVD are only the first part of fuller sets which is deemed "a rip off" and "a con" by some, but you don't need to buy the others - it's not essential, and you can also buy them on ebay - I got the CD set for £3! You can easily get along just with the first CD. The DVD is just a summary of the main points of the book for people who can't be bothered to read it - not essential. You should listen to the CD every day as part of the plan. Some people have struggled with this as his voice sounds quite funny and it can be distracting, but personally I use hypnosis CDs quite a bit when going to sleep so it was fine (although I missed Glenn Harrold!)
This version of the book does have a lot of padding - large pretty pictures, large typefaces, pages with no text at all, and there is some repetition in the text as well. In that way, it could be smaller and less glossy and therefore cheaper.
The second half of the book is a diet journal you are meant to fill in daily for 90 days. Some people find this "a con" as well. It's a very basic journal that involves minimal writing (you just tick things off a list), but it has little exercises each day designed to help you think about things and love yourself and all sorts of things. I like that part because it feels like I'm getting some therapy for my money. I believe in therapeutic journaling, so I think this is a good part of the book, and I'd say keep another journal where you can actually write more!
It is like other diet books in that they all tend to state that they aren't diet books and diets don't work. I haven't really read a lot of diet books because I do believe that they are generally a bad thing, but it seems to me that I do agree with everything PM says in here - low-fat, sugar-free 'diet' foods are the devil's work (my words, not Paul's!) and diets make people fatter. They haven't made me fatter, because I don't tend to diet, but nevertheless, I am fat because I eat too much. Or rather, I have been eating too much - I'm not now! This is where I come to being "the wrong kind of weight problem" for this book...
I think there are two kinds of fat people - people who have always been fat and people who have got fat in later life. They may look the same but they behave differently. If you have got fat because you gave birth a few times, or went out drinking a lot in your twenties, developed bad habits at university, didn't have tme to eat well looking after kids etc. you will feel differently about your fatness than someone who grew up chubby and got teased, overate for comfort after being bullied, learned how to they could best 'blend in' with the people of normal size growing up, used their fatness as armour, ate in secret, learning to move our bulk through an average-sized world without causing too much offence...that makes a different kind of fat person. Any kind of fat person can use this system, whether they have 1 stone or 400 stones to lose. Paul uses examples from many different situations. But I think the 'lifelong fatties' would probably benefit from it more because of all the work on self-esteem and body-image. If you do this properly, it is a life change and a long, slow & steady journey and that's how long it takes to make your brain adjust to being normal after a lifetime of thinking it's not. It works with the inner problems causing you to overeat, and not just on the rules of what to eat - there are no rules of what to eat!
There are also NLP techniques to deal with food cravings - not sure what I think about those because I've not tried them and haven't needed to yet. I will if I have a strong craving. Maybe it's one of those things that work if you believe it will.
I would say, buy it second-hand, follow all the steps including the CD (remember that Paul McKenna is a famous hypnotist and not a dietician, so that will be a key part of this!), give it some time and TRUST that it will work, DON'T keep weighing yourself, take or leave the DVD and NLP, keep a journal, move around more, drink water, play motivational music, eat slowly and listen to your body. The worst thing that will happen is you won't lose any weight at all, but I'd like to see you try.