I did a simple blind taste test at home on Pepsi and Mt. Dew: I prefer the HFCS version. It's what I'm used to. But I'll buy the Mexican Coke in glass bottles if I see it at a restaurant, because it's fun :)
It's not marketing as Coke doesn't advertise that different regions use different sugar sources. And it's not crap, it's chemistry. Sucrose and fructose are different and taste different. Buy, say, Pepsi and Pepsi Throwback and do a blind taste test to judge for yourself. (I'm not saying...
I drink Coke Zero. It's the least intolerable diet soda I've found. But I've never cared for Dr. P., so no comment on its diet version. What I can't figure are the Coke Zero ads that claim it's indistinguishable from Coke. Even the best diet is very different from a normal soda.