I've done both. I lost my first 20 pounds on Phase I of South Beach (which is VERY low carb in and of itself), had a year of losing and regaining the same five pounds counting calories on a high carb, low fat diet, then I've lost the next 13 pounds on Atkins. I really like Atkins, but I also like meat, veggies and eggs. If you're creative, you have all sorts of food options on Atkins.

Hope that helps. I'll be on Atkins until I'm at my goal weight, then I'll slowly transition into the maintenance plan, where I can eat more carbs.