We’ve stayed at both and I love both.
OKW is probably my sentimental favourite, because we’ve stayed there so many times - but I do love the ambience of a little village and you can’t beat the size of the rooms. Olivia’s Restaurant is one of the best sleeper restaurants at WDW. Counterservice is almost non-existent at OKW, except for the kiosks at the pools.
SSR is beautiful too. It’s great to be able to walk to the Marketplace. The Turf Club is a good restaurant and the food court - once you get use to the system - is quite good.
The bus service at both resorts is good. No matter which you choose I think you’ll be happy.