The only competition with either of the Disney water park is US Volcano Bay, and ... on technical merits VB is a fine park. But honestly, I'm so done with Universal that I don't even bother anymore.
As a teenager I loved water parks. As a parent I find the chaos, pushy wet people, and the billion gallons of liquid murder an un-magical combination. It's the kind of place that begs for day-drinking except for the responsibility of keeping my children from drowning makes that a non-starter.
Also, I have a condition commonly referred to as facial blindness which means I have to look long and hard at people before I recognize them and ... that makes me look like a creep at water parks. So ... they're not really on my list of must-dos
If we have a WDW trip over 6 or 7 nights I try to get us into a water park once at least. But ever since they took out the Shark Reef at Typhoon Lagoon, there's just not much at a water park I just gotta see.