The one thing I'll say about the Atkins diet is that I've never met anyone who has resumed a normal diet and kept the weight off. This makes it just another yo-yo diet. Of my friends who've done the diet, most of them did lose a significant amount of weight, but once they resumed a normal balanced diet, the weight came back on. One of my friends has called it a "deal with the devil" because now she can't go back to eating right. There's just no way that the Atkins program can be healthy long-term, even given the advantages of losing weight. It also shifts focus away from exercise, which is IMHO a much more important component of remaining healthy and keeping weight off.

As with all these things, YMMV, but as much as I'd love to lose 20 lbs or so, I'm not going to do it if it means never eating a sandwich again.