This is the sugar-free sibling of Rockstar. I'm a fan of sugar-free drinks with artificial sweeteners as they're strictly fewer calories and can help keep a caloric deficit. The taste of sugar-free drinks has improved significantly in recent years as we've seen with the explosion of sugar-free energy drink options, mostly from supplement manufacturers, but Rockstar sugar-free has existed since at least 2003, then called Diet Rockstar and bottled in a white can similar to the one for sale today.

Sugar-free still has the same wonderful, smooth carbonation that the full-sugar variant has but that is where the similarities mostly stop.

The sugar-free is not as smooth to drink; it has a shallower, sharper taste. Where I tasted peaches in the full-sugar one, here the taste is extremely artificial. The closest thing in my vocabulary is an extremely sour kiwi. Like you found one that was very hard, not even close to ripe, and took a big bite out of it. It is a far more artificial taste than natural kiwi but this is the closest note I can taste beyond all the sweeteners.

I wouldn't go out of my way for this one, there are far better sugar-free options on the market today.