I think it really depends on when you're going and how you like to visit the parks. There are plenty of people who are happy and content to spend a full day in one park regardless of crowd or weather circumstances...and that's perfectly fine. Our family just likes to have the flexibility that parkhoppers give us. We usually spend 7 days at Disney World and typically go in late June. We plan one full day for each park and then the other days we "wing it"...usually hitting one park in the morning, heading back to the hotel for a rest/swim, and then head to another park in the evening. This allows us to either do things we didn't get accomplished on the full day in the park or catch the things we missed the first time around. A lot of times if we spend a full day in a park, we're too tired/hot/sweaty to hang out for fireworks, so we'll just hop back to that park another day after spending a few hours at another park during the day or even after our AK full day. There have also been times where we get to a park in the morning on what is supposed to be our full day in that park and despite all of my research and planning, the park is just unbearably crowded. Because we have parkhoppers, we can just hop on a bus, monorail, or boat and head to a different park and still have a good day at a different park (as opposed to dealing with the crowds). We don't necessarily *plan* to park hop, but we love having the option to do that if we want to.