Theming made a massive difference for us. Being northererns, the winter lodge theme of Blizzard Beach was a huge turn-off. We go to Florida to get away from the snow. The BB wave pool was also a disappointment. We much preferred Typhoon Lagoon.
For us....Aquatica gets the nod over both of the Disney waterparks, though. Its got the best combination of thrill rides, tropical atmosphere, and family-friendliness. Roa's Rapids is a park highlight....a ton of fun, and totally different from any of the usual waterpark attractions. They have wonderful cabanas that are WAY less expensive than Disney's as well, complete with an in-cabana locker, fridge, bottled water, towels, and personal service from a cabana attendant.