There's actually not a great deal of sugar in these compared to others. And it's LITERALLY the only carbonated thing I drink. I don't drink Pepsi, Coke, Sprite, etc. My main enemy is Aspartame.....and these don't contain it.
Aspartame is actually much worse for you than sugar. It was banned by the FDA for years, until they were paid off to legalize it.
As for the other health issues.....well, I very rarely drink alcohol, I quit smoking cigarettes, I'm vegan, I get a lot of exercise, and I weigh less than 150 pounds, so I think any deficit from my one vice is more than countered by everything else. Having said that, I do recognise it's not the greatest habit in the world and I intend to cut down.
Because I travel and am on tour so much - I got into these to counter jet lag. Like, when I just got back from the US a couple weeks ago, I got back home at something like 5pm. I was so tired, but I obviously didn't want to go to sleep until a normal time, so I just drank one of these and was able to stay awake for a few hours to try and get back into a semi-regular sleeping pattern.