Closing time can depend on a lot of variables. If the seller is still involved, it can take a long time if they drag their feet and take a long time to sign and return documents. In other cases title may already be signed over just waiting for a buyer, so those can go faster. How attentive the closing agent is also makes a big difference. Vistana can then take a while to, but have been a little faster more recently.
We recently closed on two SVV purchases. The first, we signed the contract on 4/29 and Vistana had it in our names on 6/6. We are in the middle of the second one which we signed on 11/3 and the deed was just recorded on 11/23.
You won't have any problems using the 2017 StarOptions. However, if you want them for an early 2017 reservation you will need to have the seller make a reservation for you. If you want them for late in 2017, you can probably wait until the week is in your name.