Extra magic hour (ie. early entry) is only
good for onsite guests, including Swan and Dolphin. They have been enforcing this rule lately.....we're just back from
a 9/12 - 9/17 visit and had to show our resort key for EMH at AK, MGM and MK.
Here are the parks and days for the extra hour: AK - Monday & Friday, MK - Thursday & Sunday, MGM - Tuesday & Saturday, Epcot - Wednesday. I may have
the Saturday /Sunday mixed up between MK and MGM, but I think that's it. And to answer you final question, we find it's worth it....just another adventure!! Plus we can get back to the pool quicker!!!