We love morning EMH! Since only onsite guests can take advantage, and many do not want to get up early for it, or avoid it due to recommendations as you said, it is a great jump start to the day. You can get a lot done in the first few hours, and it is a little cooler as well. Even though everything is not open yet, you can get done the things you like that are available for that hour, and then you are already in the park when others are just making there way back to start the day, so you can head to areas you want to hit next. When we do it, we either book a late brft, like CP at MK or TH at AK(sorry for all the abbreviations!), and take a break after our first few hrs., or grab early QS lunch and have dinner planned for later. You can plan your FP for early afternoon, when it will be more crowded, and then try for more after those. Some people like to hop to another park later after they do a lot in the morning, and make their FP for there, figuring first park will get more crowded. You just have to commit to being there early, since you do not want to go to EMH park at regular opening. Now for evening EMH, it is more of a toss up. Since people are already in the park for the day, it is always harder to say if it will be crowded, so those aren't always as good. We have found that when the parks are open very late with EMH(like 1 am), it tends to quiet down later after fireworks(and formerly parade) are done, and people leave, especially with younger kids. We have gotten a lot done late nt. on those. You just have to decide which works best for you - early is always best, whether its RD at regular park or EMH at that park.