Extra Magic Hours are a great perk, but can mean that the park will get crowded. It’s nice for the first hour or so, but by 11:00 that park is usually packed, while the other parks are less crowded. If you are staying on Disney property, maybe go in for the Extra Magic Hour and then park hop to a less crowded park by 11. If you are not staying at a hotel that is eligible for EMH, definitely avoid the park that is open for the early Extra Magic Hour.