Stevia is reasonably safe

https://en.wikipedia.org/wiki/Stevia#Safety_and_regulations

You could also argue Sucralose in moderate use, too. It's for sure much safer than the old sweeteners.

Any studies on this? Things I have seen in the past seem to point to theoretical risks at massive intakes. I get the impression that sugar free sodas are going to be better than going over a reasonable daily sugar intake but could well be wrong on that.