I started it last week and have lost some weight. Not sure how well I like it, yet...need more time to get used to the food choices and not eating what I want all the time. A friend started it in January and had such great results that I decided to give it a try - figured that it was only 12 weeks, and at the end of that, I would at least be eating healthier, and maybe would have shaken a few pounds loose. So far so good!
My current complaint with the plan is that there's not a lot of online support or way of chatting with other people who are doing or have done the plan. I need more ideas for meals, recipes, etc. and their online forum is so slow moving, it might as well be dead. I'm surprised they don't invest more into that part of the plan - you really need an active community if it's going to be useful.
Let me know if you decide to do this - maybe we can start a check in or something, if you're interested.