Personally I would avoid SSR if I were looking to just buy at 1 resort. I can understand it as an add on for members who already own at a more desirable resort, giving them a home booking advantage at a good resort and then points to use at the 7 month window when something is available. It would probably work out for a while, especially if you like booking 1BRs as those are easiest to get at 7 months usually.
But eventually booking may get tight, especially after 2042 IMO. More and more members are buying SSR because it is cheap expecting to always trade into other resorts at 7 months. The more members that do this, the more competitive 7 month booking gets, which could make owners at other resorts trade out less and just use their home resort points, reducing availability further. The only thing you are guaranteed by
DVC is the availability to book at your home resort. Everything else could go away, even if it probably won't.
The last thing to think about is do you drive/rent a car or do you fly in and just get a ride on property. I would 100% avoid SSR unless you drive/always rent a car. The resort is so spread out it is a hassle to get around with an internal bus loop just to get out of the resort. It is easier to drive to most of the parks instead.