Hi!
I think that it is great that you are considering an offsite stay! I don't think you will regret it at all. It has been about 15 years since we stayed at Vistana Resort... it its was a great stay. We've never stayed at the Villages. There are lots of threads about Vistana on this board, so just search through them.
If you are really interested in a water slide, I would suggest that you try Windsor Hills. (
www.windsorhillsrent.com) Unlike Vistana, each unit is owned by a private owner, which is why the rates vary a little from owner to owner. On the other hand, you know exactly what unit you will be renting. Depending on the time of year, you can rent a 2 bedroom condo for $75 -90 per night, and a 3 bedroom townhouse, with its own private splash pool for $90 - $110 per night. Windsor Hills is about a 5 minute drive to AK, 10 min to EP & MGM, and 15 minutes to MK. Driving has its advantages, at least you aren't standing in the heat waiting for the bus to come... or having to ride standing up with your young kids because the bus is crowded.
We are renting a home with its own pool and hot tub for our November trip. No walking to the pool, no sharing the hot tub... no fighting for a lounge chair... and we get to park at our door. We are really excited!
Renting points from a DVC owner is a possibility. Again, depending on the time of year you can rent a 1 bedroom (kids would have to sleep on the sleeper sofa in the living room) for around $175 per night including tax, that's like a hotel rate of $155 per night. OKW is lovely, we have rented there in the past and really enjoyed it. But it is relatively pricey compared to offsite condos. The weekend nights (Fri & Sat) cost about twice as much, so we'd move to another property for those nights to help our budget.
Recent posters report a good stay at Liki Tiki as well with its water park atmosphere.
Good luck! You'll have a great time no matter if you decide to stay at CSR or if you opt to go offsite. It is Disney!
Lisa