I will say that the one time I came close to missing an ADR was at AoA. I got out to the MK bus stop about 70 mins prior to my ADR...it was at the Polynesian so I allowed some extra time. I just missed the bus...so had to wait 30+ mins for the next one. Now, it was at 7:30, so I knew that I could have a longer wait time (buses earlier than an hour prior to park opening tend to run less frequently. So, it finally came. And then, it was the sloooooowest driver ever. Got to MK and of course, he stopped at one of the furthest stops possible!!! So, off we went to get to the boats....no boats in sight. So, up to the monorail. And of course, it had just left!!! Waited 10 mins and one finally came. And of course, there was an issue. So we sat in a holding pattern for 15 mins!!! Got to the Polynesian about 5 mins after my ADR time.
Same type thing happened going to the GF for dinner at 1900 Park Fare....but that was from a different resort.