As promised, here's our experience with DTD transportation!
We went several times- one using Disney buses from/to CBR; one using Disney buses from HS to SSR (Congress Park stop), then walking to DTD (and the reverse trip back to HS); one driving our car from CBR to DTD and back. All were good experiences, but each depends on your plans. The buses and the walkway from SSR both put you at the Marketplace (near Wolfgang Puck Express, which was our plan for those visits), but the parking garage used if driving yourself is at the complete other end (near DisneyQuest, our plan for that visit). So really, it depends on where in DTD you are going. It's a pretty long walk to go from one end to the other!