The only issue that I have run into is, when you try and add a park hopper on during your trip, you pay for the park hopper for all days, not just the day or two at the end, for example you have a 7 day ticket and on day 5 you decide to add the park hopper, you pay for the 7 day cost of the park hopper, not the last three days, never understood why Disney does this, but I know this is how it works, I have tried in the past to do this and have not been able to unless I wanted to pay for the hopper for the entire stay