Why in the world would someone want an "energy drink" with no calories and no sodium? If you're riding at 12 mph for an hour or so, plain water will do. But if you're riding harder, in the hills or in the heat, your body needs to be resupplied with carbs and electrolytes.
I use it for the very reason that it has no calories and no sodium (more for the lack of calories, though). In my opinion, the more physical activity one can do without taking in calories (while avoiding a bonk of course), the better. That said, if you're newer to biking/exercise, it may not always be the best choice. Also, it tastes great! I also prefer solid calories during exercise to liquid (just a personal choice, really). I will say I regularly work out for two hours or more (in Florida) on just water or electromix. I couldn't always do this, it's something one has to work toward.