[EDIT] if it helps, it seems to me that having a "Pepsi Challenge" is like having an "Orange Challenge" where the other contender is a lime. It's not exactly gonna be hard to tell which one you're dealing with, even if the sample's the same size and you're blindfolded. Throw in a half-dozen other citrus fruits and yeah, I could see getting a couple of them wrong but just those two? No. Judging from the reaction here, though, I'm starting to wonder if I need to re-evaluate my sense of smell/taste. Maybe it's not only farther from normal than I thought, but in the opposite direction.

One thing you might not be realizing is that many people have absolutely shot their palates with modern flavorings, sugar bombing, etc. (though these days, smoking at least is less of a thing). I too don't have trouble telling the difference between Coke and Pepsi (and have done it blind), but if you took away visual cues, I think you'd be surprised how many people would bilge even the orange/lime test.

It turns out that they are not the same, and there's a reason lots of people order whiskey and coke and nobody orders whiskey and pepsi.

It was not better.

To me at least, Coke has more citrus notes and is a bit more sour. RC, at least in the US is slightly more bitter and also seems to have a slightly sweet aftertaste, but not that different from Coke. Pepsi is more sweeter as well, and doesn't have the citrus hit.

The more interesting difference is Sugar cane Coke, like they have in Australia, and Corn Syrup. They are both equally sweet, IMO, but the corn syrup has a different aftertaste and texture. Still mostly identical.