This article is from the Dr. Pepper FAQ, by Christopher Flaherty with numerous contributions by others.
In the opinion of everyone who's tried it and commented on it here on
alt.fan.dr-pepper and to me in person, the cane sugar version tastes
better. It's also the sweetener which was originally used to make Dr
Pepper in the first place. Personally, I think the taste of the cane
sugar product is more well-rounded and less fizzy than the one with
high fructose corn syrup.