We tried the evening EMH at the Studios last month. It was a totally insane. We grabbed Fast Passes for Tower of Terror because we overheard a CM tell someone they reopen the FP machines for EMH. After riding TOT the stand by line for everything was insane. Even the return times for Fast Passes was way into the night. So we gave up and went back to the hotel. You can do a LOT more at all the parks if you get there before opening. The first couple of hours at the MK are very quiet, especially if you go left since most of the crowd seems to go right towards Tomorrowland. The same early strategy works for all the parks.