You need to pick your poison. You either sacrifice your sleep or wait in really long lines the rest of the day. Sleeping in will not be remembered in years to come, but memories are made by experiences, and you'll have more of them if you avoid waiting in long lines.
You can have the best of both worlds by scheduling some off days to sleep in and hang by the pool. It's a lot easier to take the early rise day when you know you can get up late tomorrow. We did that, and it was great.
My DD hates to get up, and every morning is a chore getting her up for school. I started preparing her for RD months in advance after I had read repeated advice from Disboarders to do so. And I had to contend with a bit of grumbling when we were waiting to get through the turnstiles at MK for rope drop. But from the moment Mickey and all the characters rode up on the train and did their park opening song and dance, DD's face lit up and the magic hit her. The day was a complete success! We rode Buzz Lightyear twice and never waited to get on any ride. I can't believe that we walked right on Peter Pan and Winnie the Pooh that morning, when walking through Fantasyland later (around 11 a.m.), the standby line was huge, and that part of the park was so crowded, we could barely make our way through!
When the park got oppressive, and the crush of people made it unpleasant for us, we went back to the hotel and enjoyed some R & R by the pool. We went back to the park later with renewed energy and vigor and had a wonderful, stress-free time.
On the day we went to Epcot, we were both tired getting up early because we had done an Illuminations cruise the night before. But we sucked it up, got up early and got there at park opening. Good thing we did because we nabbed a Soarin' Fastpass and then were able to ride it again much later with another Fastpass. Soarin' was DD's favorite Disney ride, and she was so grateful to be able to ride it twice in one day with no wait. We had a busy day at Epcot, and would have missed so much had we gotten there late. We transferred to Universal the next day, so we slept really late. And it felt like such a luxury!
I have learned a few things from reading these Disboards: 1)Heed advice that is frequently repeated by numerous sources. They know what they are talking about. (Believe me, we had absolutely
NO intention of going back to our hotel during early afternoon, until we were confronted with huge crowds, fatigue, and blazing sun). 2)The most recommended attractions are popular for a reason. 3)Touring plans enable you to get the most access to attractions and rides on your vacation with the least amount of wait.



