All Marriott owners - whether they own points or legacy weeks - can exchange through Interval International (II) to access Marriott or non-Marriott properties worldwide. Marriott maintains Interval International representatives at their headquarters to assist Marriott owners exclusively.
The Marriott Vacation Club Destinations (points) system is essentially Marriott's internal exchange network -- if you own points, you can contact Marriott directly to use your points for bookings. Owners of traditional legacy weeks do not have access to this system unless they enrolled their legacy week into the points option (every year they have the choice to either use their Legacy week or take points). In order for a legacy owner to be able to enroll their timeshare in the points program, they must have purchased their unit directly from Marriott or from the resale market prior to June 23, 2010.
In general today Marriott is only selling points not weeks at a resort. The points allow for you to book at Marriot Vacation Club locations along with many other types of vacations such as cruises and events.
Personally I like the deeded weeks I purchased before they switched to points. It mostly guarantees I can get my weeks in Aruba. If I can't use them I can easily (so far) rent them out here on Red Week.
If you don't want to make the timeshare investment I think renting through Red Week is a great option. You can get some great deals and spend a week in great places. You could spend 10 weeks or more for a week for the price of the timeshare.
