If you're going Memorial day weekend, I would expect it to be busier than a random tuesday in May. I went this spring and the highest wait time for a slide was 35 minutes. Food lines were pretty long at peak meal times. The above poster is right, wait times aren't posted for the water parks so it's impossible to know how busy they really are.
I will say that Typhoon was WAY less busy than another Orlando water park, Volcano Bay. That park felt like a madhouse in comparison to Typhoon.