Just our personal preferences:
There's only two of us so when we go to OKW we get a 1-B/R for the space and slower pace we intend for that particular trip.
We don't like the studio that much at OKW, seems too much like a regular hotel room, kitchenette included or not, simply because of the double beds.
At the other resorts, BWV, VWL, and I'm sure, BCV, the studios feel more like a villa. I just like the layout better there with the sofas instead of the 2nd bed. Makes it seem roomier even tho physically it's slightly smaller. That plus the location of the resorts really makes studios at those locations a lot more attractive than the studios at OKW. I don't particularly care for the 1-B/R's at those resorts however because they are considerably smaller than OKW 1-B/R units, and cost a lot more points.
When we have guests with us, then we will get a 1 or 2 B/R no matter which resort we're staying at.