I have a lot of experience in this area. I own points in Disneys Vero Beach resort, Old Key West and Beach Club. I also have two other time shares Marriott's Ocean Point and Parkway International. I've owned Disney since 1995 - bought Vero Beach over the phone. Disney is by far the most flexible due to the point system. You can stay partial weeks, where most others are for a full week. You can also extend your stay by staying in a smaller unit. I have 280 points in total and have been on Disney Cruises four times with my points and I still get to stay at Disney at least once a year.
On Saratoga, it is the first resort with a 50 year life span. All others expire in 2042. If you are looking at Saratoga, I would take a look at the new one at the Animal Kingdom before you buy. It's awesome. Saratoga is just big, nothing particularly special.
Sandy M.