I'm doing this, after doing 2 months on Cambridge,and losing 2 stone. and I hate to say I'm getting better losses than any week on CD, and eating lovely food too!
Instead of atkins,which loads of meat, its lots of green veg, tofu, quorn and eggs for protein.Feeling fantastic, as Im still in ketosis, but eating!, BUT I think if your mental attitude to food is still not great eg binging, needing sugar fixes etc, I can see people could take advantage of the calorific foods, such as double cream, and cheese, and not do so well on it.
Cambridge completely put an end to my emotional eating, and that's why I decided to continue the weight loss where I could eat food again, and for me it's been fantastic
HTH!