If there is any way you can do both, you'll beat the crowds all around. We don't usually go in the summer months anymore, but when we did, we'd get up early for the early EMH park, go back to resort for a NAP (saved pool time for down day or no late EMH day), then went to the late EMH park for the evening and closed the park down. This does require the parkhopper option. That nap in a cool room in the afternoon during the hottest part of the day was the only way we could burn the candle at both ends, but we loved the relatively emptier parks.