There are basicly two types of timeshare properties: Right to Use (RTU) and Deeded property. Although grossly oversimplified, you can think of these as buying a car or leasing a car. The deeded property is like owning a car; if you take out a loan, the vehicle is yours at the end of the life of the loan. A leased property you make the payments but give the property back at the end of the lease unless you have an agreement to buy the vehicle at the end of the lease. In both cases, you get the benefit of using the car but are responsible for such items as instructions, licensing, gas, etc.
In a deeded property, you own the property once it is paid off. You still have to make the maintanance payments. One way to think of this, although again grossly oversimplifed, is to think of purchasing a condo or townhouse where you make a payment for the common area. Disney does not use this method. The deeded property can be passed on from heir to heir. Some people feel that at the end of a long time period, the property may not be worth passing on to heirs and is not worth the effort getting rid of the property. If a property is properly maintained, it should still retain value.
A RTU allows you to use the property in accordance with the agreement. At the end of the agreement, the property returns to Disney. You still have to make the maintainance payments. I believe, others will correct me if I'm wrong, that during the time period of your ownership, you can transfer the property (if not, you wouldn't be able to find resales) by selling your share or having it passed on from one generation to another. Still, at the end of the original agreement (2042 for all
DVC resorts except SSR which is 2054), the property returns to Disney. It benefits the developer to keep the property up since it will be returned to them.
One is not inherently better than the other going on the assumption that the properties are kept up; I have both. DVC is a RTU but my Orange Lake timeshare is deeded property. I enjoy them both. If I'm lucky, I will still be alive (at a happy, active 96) when my SSR agreement expires. Maybe at that time I'll have to apply for a postion at Disney as Father Time (hi hi).