The flavors of various sodas have sometimes suffered from the transition out of glass, into aluminum and now plastic. An original, cane sugar Coke in the small glass bottle is a real treat, awesome. They were better than Pepsi, much as that pains me to admit, since Pepsi has a more local origin whereas Coke was more of a Georgia thing.
Pepsi fared better in cans. Coke started to seem a little too sweet and slightly flat by comparison. In plastic, it’s Pepsi hands down. The too-sweet flatness was aggravated by the move.
Diet Coke tastes salty to me, but Pepsi does not. It’s the better of the two diet sodas as well.
One old favorite that fared even worse across the various containers is Mt. Dew. It doesn’t even resemble the original in anything but the dayglow color. The diet version is nearly undrinkable.
When I was in high school they transitioned from the glass 16 ounce bottles of Mt. Dew to plastic. That was a huge change.