If you book through Wyndham, it's unlimited access to the Waterpark. If you book through a private owner, definitely ask. Some of the owners I contacted did not have any waterpark availability, others had only one day and others had additional charges to use the waterpark. We booked through Wyndham and stayed in Villas South, which is the closest to the waterpark. We found it easier to drive over to the waterpark rather than walk.
As for the waterpark itself -- it was nice but not as wonderful as the photos and videos portray. It's divided into two parts. There's the part with the structure which is a shallow wading area. This had buckets that randomly gushed huge amounts of water. It terrified my 2-year old grandson and my 4-year old grandson adapted but was really wary. The other section has a zero entry pool with access to the "lazy river". We spent most of the time in the zero entry pool as my grandkids preferred the quiet water to the structure with the random gushes. But older kids would take over the shallow part for games of catch. There was no way to watch on the kids in both areas at the same time as it is a fairly long walk between them. There are lifeguards but my grandkids are not yet swimmers, so my husband and I needed to keep an eye on them. Also on the gushing water play structure, the kids could become hidden from view.
Reunion Resorts is a beautiful, quiet, golf-oriented property and the condo we stayed in was more deluxe than AKL and CR. (My DH and I stayed AKL last January and the kids/grandkids were at CR). It's a short drive (perhaps 10 minutes) back to WDW. Hollywood Studios is the closest park. If you turn left when you leave RR, there is a Publix grocery store no more than a two minute drive.
