The best advice I can give is follow your child's cues. On some days my DS would fall asleep and take a really good nap in the stroller. Other days, he was a raving, mouthy, crazy mess. On these days we headed back to the hotel before the bad meltdown occured. We have taken him to WDW 3 times. Once at 9mo, 2 1/2, and 3 1/2. As he's gotten older, he is more resistant to sleeping in the stroller and more prone to getting over stimulated and in need of an adult to set limits for quiet "down" time. If your child is happy or falls asleep in the stroller, than great, stay in the park. But, I think that you know your child best, and can tell if they are on the verge of having "enough". Do yourself a favor and head back to the hotel for down time. Vacation is no fun if everyone is on edge and overtired. Besides, you can always go back to the park after nap time.