It is really more complicated than giving an "overview".
Out of all the low carb diet plans...I recommend Atkins the LEAST. I would personally recommend South Beach if you are going to follow a lower carb diet-because it doesn't eliminate all sources of carbs-only "junky" ones-allowing you more healthier carbs such as veggies, fruits, and whole grains.
What you really need to do is to go out and get a copy of the book, and read it cover to cover. (This goes for any plan that you want to follow.)
There are two sections of the forum here at 3FC-a low carb section, and a South Beach section (Fat Chicks On The Beach) and you will find great support there when you decide which plan is for you.