I'd agree with Diane that it does depend on your room choice. For a studio I'd go with SSR as the extra space allowed by having the pull out sofabed will give you plenty of space for a pac-a-way crib. With a one bed I'd go for OKW. If you're child had been a little older and needed a real bed I 'd have gone with OKW for both studio and 1 bedroom.
If you'd prefer not to be too far from your room to eat OKW has Olivia's which is a full service restaurant, SSR on offers Artist's Palette which is a food court ( I'll accept a very nice food court, but still just a food court) but SSR does offer slightly better access to DTD and all the restaurants there.
At the moment I think OKW offers slightly better recreation choices ( pools etc) than SSR as you have a choice of the main pool (with slide and kiddies area) , Turtle Crawl pool area and two "quiet pools" . As SSR grows I don't doubt they will match ( maybe surpass) OKW in this aspect, but IMHO not yet.
I don't think you'll be unhappy at either resort, for me the biggest factor would be the space in the studio for a pac-a-way crib so I'd go with SSR , but your own priorities ( or unit choice) could swing that choice.