Instead of hemming and hawing (which, by the way, is a term now in my vocabulary, thanks to my new job in West Virginia) I'm just going to jump right in.
There is no difference between Sierra Mist and Sprite. Like, none. At all. Whatsoever. I think if you'd blindfolded me and made me try them both I wouldn't have even known they were different. Not even a little bit.
7UP, on the other hand, was full of all kinds of weirdness. First of all, it doesn't claim to be "lemon-lime soda" like the others. It doesn't claim a citrus flavor or even a fruity finish. It just says it's "crisp" and "refreshing," which is super helpful considering all those sodas on the market that advertise themselves as "flat" and "icky."
We couldn't quite put our finger on what was wrong with 7UP, just that it was gross and that we didn't like it.
Moving on, we polished off a good amount of Sierra Mist and Sprite trying to come up with some grand revelation that would prove a true winner of the beverage game.
There wasn't one.
All I can tell you for sure is that the Sprite bubbles were bigger than the Sierra Mist bubbles, and really, I've never heard of anybody buying soda based on bubble size, so I'm pretty sure that's useless information.
Since there was no apparent winner based on flavor, we turned to nutrition labels to solve our dilemma. As it turns out, Sierra Mist registers lower sodium and lower carbs than Sprite, plus it's made with real sugar. No, seriously, like, REAL sugar. You know, that white sandy stuff we used before we discovered we could squeeze health hazards out of corn and use that to sweeten shit. Despite it's lack of a unique flavor, Sierra Mist obviously wins for its less menacing list of ingredients.
Pepsi: 2, Coke 0.
What's your favorite soft drink?