We visited during a Run Disney event and it pretty much ruined our last day, as transportation was so snarled up. Our "first bus of the day" from AKL took over an hour to reach MK, and when we went to leave MK a couple hours later bound for HS where we had Fastpasses waiting, we had to choose between taking the monorail and the boats, because the wait for buses was expected to be 60-90 minutes, since the roads were still blocked by "runners." [*see footnote] So from MK, we had to take the monorail to EPCOT, go through security again, walk the entire way through EPCOT from the main entrance to the International Gateway, and then catch the Skyliner to HS, where we speed-walked to our about-to-expire Fastpass attraction. So looking on the bright side, we got to do a half-marathon through Disney property without spending an extra dime.
Never again!
*Footnote: This event was only a
half-marathon, and from what we saw, the Disney definition of "runners" in that context is "hundreds upon hundreds of middle-aged women of ordinary build, wearing tutu skirts and mouse ears, shambling along the street at a relaxed walking pace."