I "Somersized" quite a bit back in the day. I was quite successful with it throughout my late 30s and early 40s, but I've found that as I have gotten older (now 49), my body is changing, and I can't handle the carb-only meals. I'm doing the Newest Atkins now, and it's quite a bit like Somersizing if you Somersized doing only Protein-Fat-Veggie meals. I have never been overweight since I started Somersizing (12 years ago?), and always go back to some version of it if I've been overeating and need to lose a few pounds. I'm doing the New Atkins now because I got close to the top of the "normal" range for my height, and I prefer to be in the middle of that range. I got there during the holidays because I was eating bread, potatoes, pumpkin pie, etc.
As far as the "800 kcals/day" thing goes - Somersizing is not a calorie counting diet. I did the diet, and recommended it to dozens of people who were successful on it, and the lowest cals I ever ate daily on it was 1500, and as far as I know, that was the norm for my friends/colleagues as well. I usually ate 1600/day. I actually coudn't eat any more than that because the protein-fats-veggies meals kill my appetite. Right now, doing only protein-fats-veggies, I can barely eat 1400 cals a day, and have been eating 1200 or less comfortably. (Why do I ever stop eating this way? Darn holidays with all the delicious carb heavy food!).