Hey Reb,
I do not know the differences between Atkins and South Beach, but they are similar. I did SB 2 yrs ago and lost 35 pounds, it was rough the first 2 weeks (no fruits and very little carb action), but then the cravings were gone and it was almost easy. Use common sense and remember that its not just a diet til you get the weight off, but ideally its a new way to eat to maintain the new bod, too
good luck