Tried it a few years ago. I only did the 2 week induction, before my MIL (a nurse) nearly had a heart attack over what I was eating and begged me to stop. I really don't see the problem with it medically for a short term thing. It just makes your body behave differently and you end up burning your fat as fuel rather than the carbs. I know you can eat more carbs after the two week induction. But yes you can eat cheese, cream, fry ups etc, but what about fruit? bread? potatoes? rice? pasta? could you really go a month or longer without eating them, in return for fried eggs and smoked salmon everyday? I know you say you've tried SW (and so have I, and failed ) but the SW does offer you more variety, you CAN have eggs and smoked salmon for breakfast everyday on a red day, but you can also have a bit of pasta with your bolognese or a sandwich for your lunch.
I suppose the only way to find out, is to give it a go, if you google ATKINS, you'll get loads of ideas for low carb cooking, if you get on with it fine, if you don't, well, you'll have to look for another one.
GOOD LUCK!!
(says she, who is starting the 'Southbeach' diet, next week, after the Mumsnet summer party of course!)