I have stayed at both and enjoy both very much. I do give the slight edge to SSR. The main pool at SSR has a zero entry, two slides (one of them toddler friendly), a Donald Duck splash zone and its just a very nice pool. There is also the second feature pool in the Grandstand area, it has spray cannons and splashy things kids love. And beginning June 30th, there will be a second "main" pool in the Paddock that looks incredible from the mock up thing I saw on another site.
The OKW main pool is fun, it has a sandy area my dd always loved to build sandcastles in, but there is no zero entry and only one slide that is more for older kids who are strong swimmers. Also no splash area at the OKW main pool.
I also much prefer the dining options at SSR as far as counter service, but enjoy Turf Club and Olivia's about the same. I do like it that Olivia's at OKW serves all three meals, Turf Club only serves lunch and dinner.
We have used the busses at both, both with no problems although I do think SSR's bus route as it makes the various stops in the resort goes quicker.
OKW is more themed, and I do love the tropical theme, and the large units. I do have to say though, the lack of elevators can be an issue. We never thought it was when we were on the second floor but the last unit we got was on the third floor and that was not a lot of fun at the end of a long day. If we had a stroller, I would have been very unhappy. Be sure and request a first floor room (there are four bldgs that have elevators as well) if you have concerns with stairs.
I do agree that for families, if you are going with a studio, OKW with the two beds and a bit more space works better. We have done an SSR studio and an OKW studio for our family of four and while we do prefer SSR a bit over OKW as a resort overall, the studios at OKW worked so much better for us.