I lost a ton of weight very fast on Atkins the first time but it didn't work as fast the 2nd time and didn't work at all the 3rd time. The first 2 times as soon as I started eating the Atkins breads & allowable snacks, the cravings would hit me like a ton of bricks & eventually I'd eat off plan & that would kick me out of ketosis and my weight would balloon up quickly. By the 3rd time I knew that it was the processed Atkins foods that had grains triggering my cravings and I avoided them but I just wasn't loosing weight even though I stayed strictly on track. It was sad and I really wished that I had stayed with it the first time since the weight came off really, really fast. I lost weight faster on Atkins than with any other plan except for the intense exercise program, P90, along with low calorie eating. For a meat-lover like myself Atkins is definitely easier than any other plan I've tried.
Now I'm eating a modified South Beach, with no grains and very, very limited starchy veggies since carbs immediately cause a weight gain for me. This seems to be working out for me.
I think Atkins is great. If you're doing it for the first time my advice is to stay strong and stay with it until you've reached your goal weight b/c like many people it may not bring you the same results the second or third time around. And if you're having unusual cravings, check for grains in the processed low-carb foods. I think some of us just can't eat grains without cravings or weight gain.
Good luck to all of you!