In the BWI, you get 2 queen sized beds. In the studio, you get a queen sized bed and a full size sleeper sofa. In the studio, you get a toaster and a microwave oven in addition to a refrigerator and coffee maker (which I believe are both in the BWI rooms -- the frige at BWV studio might be a little larger). In the studio, you'll also have a vacuum (like you'll use it?!), paper plates, plastic flatware, a can opener, dish soap, glassware, and cupboard space for food, etc.
The big thing for us is that BWV is closer to DHS, our favorite theme park, so we've only stayed at BWV (2x this year). I didn't think we'd use the microwave, but we did.