Yes, there is a major difference in flavor. It's not as harsh as regular Coke, and it seems a bit sweeter too, almost like RC. I'm normally not a bit Coke fan; I rank it third behind RC and Pepsi (and below some generics colas!), but this version is MUCH better.
I haven't found anyone around here who carried Pepsi Throwback, a sugar-sweetened version of Pepsi. Apparently it was only a limited time thing, so I guess I'll never find it.