DVC studios to me are ideal for couples but not for four people, be they families or all adults. The sofa is great when its just two people, but when you have to rearrange furniture to get the sofa bed made out, it gets old quick. And I have stayed at my fair share of studios and those sofa beds are not that comfy. I never cared when it was for my kids lol, but as an adult I would not want to sleep on one if at all possible.
I would go for the WL room for sure.