You do not mention when you intend to go. In choosing be aware that the VGF studios can fill very quickly at the 11 month booking window open only to members who own at the resort, and during the last quarter of the year and through marathon weekend in Jan, there are times that you cannot get them even at 11 months out. With Poly, you should try to book within the 11 month window for times during that last quarter of the year and through marathon weekend in Jan, but for most of the rest of the year, you will find Poly open at the 7 month boking window when members of any
DVC resort can reserve there.
As to size, the VGF studio is close to 375 sq ft and Poly rclose to 450, although a good portion of its additional sq footage is in its larger bathrooms.