When we stayed at the Polynesian, the buses were on a shared route. Sometimes shared with WL, sometimes with CR, sometimes (frequently) with GF. The bus to DTD always seemed to have the longest wait times.
When I was as BWV in January, I had a car in order to drive to southern Florida the last day of our WDW stay. We decided to hit DTD on our way south. That was the first time I had driven myself to DTD....man, I was in shock. It took about 12 mins from the time we got to the parking lot, into our car, then drove to DTD, and then finally found the right area of the parking lot. The finding the right parking lot took longer than the drive there!!!!
I realize that the Polynesian is further away from DTD than BWV but it may very well be worth it to drive. THe parking gets a bit crazed in the evening though!