I think this will end up being like Tower of Terror vs. Guardians to me. Had Disney built Guardians from scratch exactly the way it is, I'd enjoy it and think it was a very acceptable E-ticket attraction. But knowing how incredible Tower was before, and seeing the rather lame retheme in so many areas (where they cut costs is painfully obvious), I'll never enjoy it as much as I could have.
If Disney built this Tiana water ride from scratch, I have a feeling it would be a really great addition to the parks. But Splash (when properly maintained) is such an amazing and iconic attraction that I hate to see it go. Plus, I fully expect Disney to cheap out on the retheme, leaving it mostly looking like "Tiana's Splash Mountain Adventure", which will disappoint me every time I ride it.