We have stayed in wheelchair accessible and regular 2 bedroom units at OKW. Our whole family has stayed in a regular room at VWL. DH and I stayed in a one bedroom regular unit at BCV and DH and older DD (not in a wheelchair) stayed in a studio at VBW.
Youngest DD uses a wheelchair full time. She's a good driver and it quite independent at home. She uses a narrow adult wheelchair (seat is 14 inches wide and 18 inches long, for some perspective). She has no problems getting around at OKW in a regular or wheelchair accessible unit. She can get everywhere without problems and without having to move anything or being in the way for anyone, even when the sleeper sofa is made into a bed. She is able to go out on the porch and her wheelchair fits well at the table in the great room, even with 4 to 6 chairs aound the table. Both bathrooms are large enough to drive a wheelchair in and close the door, even in the regular units. The raised seat toilets in the handicapped rooms are a bit high for her (she's only 5 feet tall and is done growing). Wheelchair accessible units are scattered thru the resort. One of things we like is that it's so easy to get out of the unit - just open the door and go down the sidewalk. Bus stops are usually not far away and if you drive, the car/van is very close to your unit.
DD doesn't use the pool to much (her idea of a perfect pool would be the temperature of the hot tub). I don't know if they will add a zero entry when they renovate the main OKW pool. I'm quite certain they will at least add a set of "bump steps" for access since they have added these to other pools as they were renovated. I've been told that the pool at Old Turtle Pond does have bump steps.
When we stayed at VWL, we had a lot of problems because of the smaller space. We were in a regular unit, so I don't know if these issues would be solved by having an accessible unit. There were no accessible units to look at when we have taken tours, but the
DVC CMs told us the rooms were the smae size, just arranged differently.
If the sofa sleeper was made into a bed, DD could not get thru the great room at all, so she was either trapped in or out of the second bedroom. It was not possible for her to get on the little deck (and even if she could, the wheelchair would not have fit because the deck is narrow). She could not get close enough to the table and when she sat there, only 2 other people could sit there since she partially blocked the bench seat. When she was at the table, she also created a bottleneck to get around.
We were all the way down the hall from the elevator, so to get out, we had to walk in the wrong direction to get to the elevator and then backtrack to get to the bus and boat stops.
When DH and I stayed at BCV this summer, we were also looking at it from an accessibility standpoint. We would have the same problems there as at VWL. It would be nice to have the closeness of 2 parks, but for us, the extra room at OKW (and not having to trip over the wheelchair or have DD upset because she can't get thru someplace) is the most important for us.
If you have a small child, the places may look roomy, but remember that the wheelchair grows somewhat with the child. You will have plenty of room to get around at OKW, but I would definately suggest taking a tour to see what would work for you.