SSR is my favorite resort, so I put a plug in for it. But as others have said, SSR and OKW are pretty close to one-another when it comes to the main things to look at.
They're both large resorts in the Downtown Disney area. Both are large enough that they require internal buses (or a 5-10 minute walk) to get between different sections of the resort. Both are WONDERFUL if you have a rental car because you can park right by your room.
Turf Club and Olivia's are both on our "must do" list for just about every trip. For bar and quick-service options, I prefer the choices at SSR.
I personally prefer the decor of SSR over OKW's, as well as the overall theming of the resort. I also like the pools better at SSR.
Ok, I'll raise my hand and admit to being lazy, but lack of elevators in the OKW buildings was a turn-off for me. We've learned to request a first floor room. (At all other resorts, our preference is for top floor to get the view.)
The large porch at OKW is wonderful!
The 1 bedroom units at OKW are larger (1005 sq ft as opposed to SSR's 714 sq ft).
OKW is slightly less points that SSR. (I think amypetecar meant to say it's 1-to-3 points less per night. It certainly is 1/3 less.)
We've tried every location at SSR except Carousel. (I may be crazy, but I'm going to actually request it next time just to say I've done them all.)
Grandstand: Nice quiet pool with a water play area, bar and drink station. Has a community BBQ area. Relatively close to the Carriage House (location of the front desk, Artist's Palette restaurant, Turf Club, store, spa, and main pool). First bus stop on the theme park route means you're usually guaranteed a seat when going to the park, and first one home at night.
Springs: Closest to the Carriage House. Very convenient to the main pool, shopping and dining. Short walk across the bridge to the Paddock and the new pool and quick-service restaurant there. Last stop on the bus route, though, so may experience some standing-room only buses during busy hours. From the Springs, you're close to the bar and drink refill station at the main pool.
The Paddock: Has the newest themed pool and QSR. There's no bar, but they do have bottled drinks and a refillable mug station that includes both sodas and hot beverages. If you're in one of the buildings close to the pool, it's also convenient to walk across the bridge and get to the main pool or Carriage House. This is a very large section, so be specific with your request (if you can do that any more) and ask to be close to the pool.
Congress Park: Closest to Downtown Disney. Very nice to be in the Marketplace one minute, and your room a few minutes later. The pool here is truly a quiet pool, and has a neat view of Downtown Disney while you're swimming. This section has a nice playground and BBQ area.
Carousel: If you're into a really quiet location, this is for you. Out in the middle of nowhere, this section is conprised of a couple of buildings fit into a back corner of the resort. You need to cross the street to get to the bus stop, and need to walk to get to a pool, as there's not one in the section.