There is a bus that goes to DTD, with a stop at SSR on the way. It's a cute, fun little ride.
We have always had good experiences with the bus transportation. Just as an FYI, every bus stops at the Hospitality House (the main area, with check-in, gift shop, restaurant,main pool) last, so if you are in a unit that's a bit of a walk from the HH area, you can hop on any bus to get there.