We've stayed in the 1BR at SSR, a studio at OKW, and been taken around a 1BR at OKW.
The 1BR at OKW wins hands down!!! The 1BR at SSR was very comfortable for us, but the OKW 1BR seemed like double the size! If you're trying to decide between the two in terms of 1BR, then go for OKW.
As for the studios, well I'm not so sure. The trouble with the OKW studios is that they are in the corners of the buildings, so rather than having a straight rectangular room, it's sort of triangular. But because of that, you do loose a bit of floor space. We never saw a studio at SSR, but have been in the AKV and BWV demos, and while they are technically smaller in size of floor space, they don't feel smaller, if that makes sense?
Our room was also very dark too. Awing out front, a patio that you could hardly open the door onto without hitting someone in the leg if already sat out there. Then there was just shrubbery as tall as the windows on either side which didn't help!
I know as a family, if we were debating between a studio at SSR and OKW, SSR would win out. But then everyone doesn't like the same thing. I know a lot of people who would prefer OKW over SSR; we are the over way around.
A few other things that bug me about OKW:
The place is huge, and if you have not got a car, then it will be the internal bus service for everything. We had a room in their 'hospitality' section, which is the closest set of buildings to reception/food/shops. It took me 10mins to walk from my room to the counter service/pool area.
While they have a TS restaurant on site, where you can sit and eat, the CS place is outside. The ordering desk is outside, and your food is served outside. The seating is just some benches with umbrellas - rubbish for sitting under in the summer heat or the pouring rain. There is no indoor area to sit and eat CSs.
The Concierge desk shuts at 10pm.
The Bell Service was great however. We switched hotels mid-stay and had things in our fridge and freezer from SSR. Bell Service at OKW was great at storing in the fridge/freezer and were speedy at delivering when we got to our room! OKW also have a better selection of DVDs for rent!