I didn't know what Propel Water was, so I looked it up online. I couldn't find a lot of resources that weren't put out by the company that makes it, but I did find
this article about its effects on kids.
From what I can see, I'd say that if you're using Propel Water as a replacement for soda, it's a great choice. It doesn't have any calories or carbs, which is pretty good. It does, however, have 80 mg of sodium. To ground that number in reality, a small french fry from McDonald's (known for being salty, of course) has 134 mg of sodium.
In the end, no drink is better for your body than pure water. You're right that artificial sweeteners aren't good for your body. I would never call any kind of sports drink exactly "healthy" or good for weight loss, but they definitely have their place. If you're looking to quit sweetened drinks altogether, this could be a great intermediate step!