We've stayed numerous times at the Poly and the buses are of a hit and miss situation. Seems to me that during the slack season, there are less buses running at all the resorts, medium waits and during peak and holiday seasons more buses but more people. We've waited anywhere from 2 minutes to 30 but we're on vacation, whose counting. When we're at Disney, no watches are allowed in our group, we're not timing anything and need to be anywhere in no set time.
Experiences from past trips seems to be that no matter where we are off to, the bus just left or just pulled out, hence the next 20 minute wait. Since we tour with no plan, been there over 38 times plus, we just grab the first bus that pulls in and head to that park, or upon arriving switch to another bus to where we would like to go. The buses to us are pare of the experience, no where else do they transport you around for free. Only place you can leave your car for the whole stay and have others escort you around.
Time from Poly to DTD, don't think its an hour but its a good standard to go by if your trying to make a certain deadline. No sense rushing, had a CM, as we ran to catch a bus, you're on vacation, why run, another bus will be along. So true, take it at an easy gait, relax, see it all, landscaping, trees and scenery.