I am planning a winter trip to the Dells (Jan or Feb) and would like to stay at an indoor waterpark. It will be a family of four that includes two girls ages 12 & 14. I've been looking at Wilderness, Kalahari and Great Wolf but just can't decide. Kalahari is the most expensive so I'm just wondering if the extra $ is really worth it or are the others just as fun? It's just for a long weekend so we'll really only have 2 days. Any suggestions?