With Sunset World you buy contracts. That resort family is affiliated with RCI as its exchange company. With RCI most of the resorts have 2 resort codes one code is for mandatory All Inclusive the other code is for optional All Inclusive.
I own at Sunset Fishermens Resort and Spa this is located in Playa Del Carmen, MX I own 10 contracts because I sold 2 this year. I obviously love Fishermens, but the Sunset sales machine is not a company you want to deal with.
I know Sunset is still selling memberships out of the other locations. DONT BUY ANYTHING. In my opinion there are no purely RCI memberships that are not linked to a home resort.
There are things called vacation club ownerships but they are worthless as your always competing with billions of other owners that want the same resort locations.
If you want to have an RCI membership just let someone give you a contract for free that exchanges into RCI
Due Diligence is the key.