Followed it religiously for 5 months when the book first came out.
Ate around 3000 cals during no carb days and 4000-5000 on carb day.
My carb day was Sunday, which was fun, but I felt sick if I overdid it. I pumped up like a balloon on Monday, I was watery and bloated. Bloat was all gone by Wednesday morning. I looked flat as a pancake during the week. Training on Thurs, Friday and Saturday was pure agony. I felt like death after training legs. People in the gym said I was white as a ghost after training legs. I needed lots of caffeine to get through the rough spots.
Overall the diet is great for fat loss, but not very good for muscle size.