I've long wondered about this sort of thing. I have friends who drink no-sugar drinks, but I can't stand them. Even the ones everyone says are fantastic taste bad to me.

I wonder if there's not some sort of genetic connection influencing how some non-sugar sweeteners taste, much like the genetic link with cilantro tasting terrible for some.

Might the commenter really not be able to taste the difference? To me, it would be stark and unmistakable, but perhaps that's not true for everyone.

I don't eat fast food or drink normal/diet soda enough to taste the difference, and the difference got even smaller when McDonald's in my country moved away from Coke Light/Diet Coke, and only sold Coke Zero as the no-sugar alternative.