dinabean, I generally avoid all artificial sweeteners on principle (including natural stevia extract). Not only are many of them suspected carcinogens, but they just don't work for weight loss. Here's a short explanation from Wikipedia:

Animal studies have indicated that artificial sweeteners can cause body weight gain. A sweet taste induces an insulin response,[citation needed] which causes blood sugar to be stored in tissues (including fat), but because blood sugar does not increase with artificial sugars, there is hypoglycemia and increased food intake the next time there is a meal.
A teaspoon of sugar has 15 calories. I just don't see the need for artificial sweeteners, and I prefer my food to be chemical free to the extent possible.