We've never had a problem with Disney transportation. Being park people, I guarantee it is easier to head straight to an ADR directly from a park, than to return to your resort, walk to your car, then drive to your ADR. As for a morning ADR, it is also easier to take Disney transportation from that early ADR, to your park of the day, than to drive back to your resort, park, and take Disney transportation to parks. Just allow yourself approximately one hour, some say 1 1/2 depending on the ADR and time of year, before ADR for travel, most of the time we're early and use that time to tour the resort.
DISNEY TRANSPORTATION is our vote, never has let us down.