Everyone has a different opinion, obviously, but the studios sleeping 5 at GFV is what tipped us over the edge to finally buy
DVC. (We have also stayed at all three studios that sleep 5--WL, GFV and Poly--and are eagerly looking forward to using our points soon for BWV and BCV.) For us, we are perfectly happy spending a week on top of each other in a deluxe hotel room at Disney, and there's really not much of a difference in room size or configuration between a deluxe room and a DVC studio. For me, the extra space would be nice if we stayed in a 1 or 2 bedroom villa--don't get me wrong--but I don't NEED that space, and I don't want to do laundry or cook while I'm on vacation.
I'd be very happy if all of the DVC studios were converted, but I will likely continue to keep Poly & GFV as our primary places to use points when we travel with our family of 5 due to the split bathrooms in the studios--that's a major bonus for us and is worth the premium points.