i have! i've been to the one in wisconsin
it's been a really long time, but from what i remember, the water park is very very kid friendly. if you're looking for thrill rides, this is not where you want to go haha
at the wisconsin dells location, it's mostly kiddie pools and lazy river. there are two faster rides- one that looks like a giant funnel (which sounds really fun, but i remember it wasn't very fast and people's inner tubes kept slowing to a stop before they got to the hole at the bottom of the funnel and everyone had to scoot on their butts towards to tunnel to get out hahahajajaja), and this 'racetrack' thing which was basically your standard waterpark slides.
if you're going with kids less than 10 years old, then i think it'll be fun, but if you're above that age, you'll probably get bored pretty fast...
hope that helped!
