If your group was larger, I'd say go for OKW since those 2 BR are larger than the ones at SSR. However, with only three of you, you will have more than enough room at SSR.
I love both resorts, but do prefer SSR a bit over OKW (I have stayed at both resorts numerous times).
I think you made a great choice.
THV's are very remote and require a bus to get over to the main part of SSR to then switch busses to get to the parks. Or you can walk but its a bit of walk. The main part of SSR is wonderful, the THV look neat but I would not stay there unless I had a car or really needed that add'l bedroom for a two bedroom price.