I am a veteran of the Atkins diet. I lost about 25 lbs in the space of about six months. This was right before I got married - my wedding dress needed major alterations
You will have to watch your carbs for the rest of your life, though. You can never again have simple sugars or white flour (which is a good idea anyway). Also, once you've lost whatever weight you want to lose, you go into the maintenance phase, where you eat just enough carbs to maintain your weight. I'm not sure how healthy that can be... (I didn't stay in maintenance like I should have, and to make a long story short, will be starting induction as soon as I'm over this horrible cold I caught.)
Good luck!