I can assure you that Dr Pepper with cane sugar tastes distinctly different from (and better than) Dr Pepper with corn syrup. In areas with a significant Jewish population, the recipe for Dr Pepper and many other sodas is changed back to sugar during Passover (corn syrup is made from corn, corn is a grain, soda is liquid, therefore soda with corn syrup is not kosher for Passover), so it’s not particularly difficult to do a direct comparison.
Some years ago, Anthony Dias Blue, food and wine critic for WCBS-AM, held a soda tasting, in which he judged Dr Pepper the clear winner.
John W. Kennedy
“Compact is becoming contract; man only earns and pays.”
– Charles Williams