We have gone many times in Sept. At first, I had us up doing every EMH, but quickly realized that a lot of the rides at MGM and Epcot that were open on EMH were not rides my kids could handle (RNR, TofT, Test Track etc.). Now, I usually do one MK EMH and AK EMH (to get on the Safari ride first thing) during our stay, but other than that, we sleep a little longer and go to a park that does not have EMH. I agree that it pays to get going to a park when it first opens as the heat and humidity is still really strong in Sept and we are zapped by 1:00 and head back to hotel to swim and relax until about 4pm and then head back to parks/restaurants. Sept is great as you can accomplish so much with low crowds!