Go with OKW. I've stayed at both and I consider the resorts to be pretty much the same in terms of style, amenities, location and buses. Neither one has any real benefit over the other. People say that OKW has a really good slide for the kids in the main pool, but i've never been to the pool at OKW.
The reason I say to book OKW is because the points required for OKW are very low and the rooms are HUGE. You should be able to get a few extra days or even get a one bedroom instead of a studio. Which is excellent for getting some alone time, or putting the kids to sleep for a mid-day nap while you relax in the living room.
Both resorts are wonderful resorts. The advantages of SSR over OKW are proximity to DTD and counter service option. If those are not important to you I would choose OKW.
You didn't mention when you are vacationing. If it is in the near future, both resorts have similar pool experiences. However, SSR will have a huge new pool, with a wonderful kids play/water area that they are adding.
If with a young family you are going to be doing a lot of studios the size of the OKW studios would be the deciding factor for me (not to mention less points)
We are traveling 12/1-12/12, so I called today and was able to book the first 7 nights. We have wailisted BLT and BWV as wel....really keeping our fingers crossed for BLT!