Like Ross said, as long as you only have them once in a while, there's no ill effects.

A lot of artificial sweeteners cause some mild bloating and water retention in most people.

Also, anything sweetened with Splenda brand sucralose, you can toss their idea of 'diet' meaning 0 calorie. Splenda runs 2-3 cals per teaspoon. Sugar runs 4 cals per teaspoon. You do the math on how much you're saving there ;)