My parents were able to trade DVC points through Interval International for a one week stay in a 2-bedroom at the Royal Islander in Cancun. In fact, that made it possible for me to join them on the trip, and we just got back last Sat. The resort was very nice. The 5 hotels that are part of the Royal chain downthere were some of the few to escape Hurricane Wilma with little damage. The room was comparable to a 2-bedroom at a DVC resort with the exception of there being no washing machine or dryer in the room. There are, however, laundry facilities on site.
If you have any questions about the resort, let me know.