RPM,
I have been on the SBD for over a year. I lost 30 lbs in the first three months and have kept it off. My father in law got me hooked on it as he lost over 100 lbs. The thing with this diet is that it is very hard for the first 2 weeks, because you are weening your body off of all the stuff you have always craved. After the first 2 weeks (phase 1), it gets much easier because for one - your cravings for the "bad stuff" is much reduced, and two - the diet becomes less restrictive (phase 2). After you lose your total goal in lbs, you go on phase 3 which is even less restrictive, to maintain your new weight.
The key for me, though, is that I didn't go on the diet to lose weight, I went on it because of the health problems I was having (heart related). Ever since then, my heart problems have all but disappeared. The weight loss is just "gravy".
By the way, don't restrict yourself to portions that don't fill you up. You can eat as much as you want of the "good stuff". That includes things like eggs, low fat cheeses, lean red meats, etc. I typically eat 4 eggs, canadian bacon, cottage cheese, yogurt, and strawberries for breakfast nearly every day. And snack at regular intervals, too. Just make sure you're snacking on the "good" things like peanuts, cottage cheese, and various vegetables, and NOT carb filled stuff like chocolate, crackers, ice cream, etc. I have NEVER gone hungry the entire time I have been on this diet.
Good luck from a fellow MD'er.
MDK