Last trip, I planned out that we would go to each park that has the EMH's during our trip. Well, apparently so did everyone else. The lines at the bus stops that morning were ridiculous for MK, who had them that day. This was around 9am, so the parks were already open and it was out the stands! After waiting 30 mins in line and seeing AK busses come and go with no line, we changed plans and hopped on the next empty bus to AK. After the park closed at 5, we headed over to MK and enjoyed the extra evening hours.
To be honest, that seemed to be the best way to take advantage of them. I'm sure the lines were longer during the day and we pretty much walked on to each ride in MK that night.