I don't worry about aspartame. Some people have specific reactions to it -- headaches in particular -- but most people don't.

The research telling us how bad aspartame is was largely funded by the sugar industry. The same industry that funded research showing that saccharine -- Sweet and Low -- causes cancer. The same industry that got cyclamates banned in the US (but not Canada) because it causes cancer. They are putting out all sorts of claims about Splenda/sucralose now.

I use whatever is available and tastes good.