There is a risk involved with renting points but if you use someone that you believe you can trust then the risk factor fades. But there is still always that possibilty that the DVC can cancel your trip or Disney can cancel this trip if the DVC member has not paid their dues. We actually rented points from three different DVC members for our upcoming trip. And I am sad to say that one of the members have declared bankruptcy and I am not sure if my reservation will still exists when we check in and I will be out the money I paid for the room. But the other two members I rented from have been great.
If you really are set on wanting to stay at a DVC property then I would rent points. For this trip we really wanted to stay at BLT for the proximity to MK and traveling with our DS and then having a double stroller. Now that the monorail hours have changed, I doubt we will ever stay at a DVC property. We are going back again March 2012 and I booked through
AAA to stay at POR in one of the royal rooms.