Well, I reckon the guys/gals that lost 200Ib and 80Ib speak volumes for the diet.
It's all about running it safely and properly, and if you do that you will likely to be very pleased with the results. Sadly, for some people these types of diets aren't suitable and they are tough for most of us to adhere to over any length of time. I reckon it's all about listening to your body, and if you do that all will be well.
Very happy for you guys, well done!
Craig