Our Experience with EMH evening.
6/16 (Epcot) - No trouble getting a wristband. Hours were 9-12. At 9:00, we got a FP for Fast Track (9:40 to 10:40), standby wait was over an hour. Soarin was also over an hour. We spent 45 min in Living Seas, looked at the fish and enjoyed Crush, then used the FP for Fast Track and left Epcot before 11.
6/17 (MK) - Hours were 11 to 2. No problem getting wristband. Mob scene. Forget the mountains or Buzz. It is good for the less popular attractions. We saw Philarmagic, Haunted Mansion, and Country Bears with no waiting and left around 12:15 AM. There were still many people coming into the park then. Many were pushing strollers.
6/19 (MGM) - Entered park around 8. Hours were 10 to 1. No problem getting wristband. Another mob scene. We didn't even use EMH, we caught Fantasmic at 9, then left the park. It was starting to rain hard, so it may have cut down the crowd some, but we didn't stay. There's not that many attractions open to justify the crowd.
6/20 (MK) - No problem getting wristband, but we didn't even stay. It was just too crowded.
However, we tried the reverse theory. We entered MK at 9:15 the next morning and had an extremely productive stay. We were able to ride all 3 mountains, rode Buzz twice, rode the carousel, Peter Pan, Pirates, HofP, Tiki Birds, and Treehouse. We ate lunch Pecos Bills and caught the train to the main entrance and left MK at 2:45