I think sparkling water is a great alternative, but I'm skeptical that all the fake sugars will turn out to be much better in the end. We seem to have a habit of replacing known bad things with things that we just haven't found out are bad yet.
If you're already in the middle of the healthy BMI range and not having trouble keeping a healthy weight, I don't think there's been a demonstrated harm.
It’s worse for people attempting to lose weight because it apparently doesn’t work for that either, and this is the main reason sweeteners are used.