There are advantages and disadvantages to both strategies. The nice thing about transfers is once the points are in your uncle's account, they are there and he can book your room and control the reservation. WIth a rental, the original owner would control the reservation until you check-in, so if they get behind in dues or mortgage payments, your reservation could be lost, but the vast majority of owners are fine to deal with. I think working through your uncle would be more comfortable, if you can find a transfer.