We got a package through Costco travel. I agree that the preferred seating thing wasn't huge ... except that I realized that with Aladdin, you could show up just before the show and still get a great seat on the floor level, with your preferred seating. The mezz. would have been better for some of the special effects, but the people lined up in the hot sun for an HOUR before the show.
That said, Costco had a great deal where in addition to the souvenirs, etc. you also got a $150. gift card, which we used for food and souvenirs. Plus they also offer a dinner for two off the regular menu at some of the restaurants at the hotels, PCH Grill, Hooks Point, and a couple of others... OR a character breakfast for your whole group. We took the dinner at Hook's Point. It included appetizer, entree and dessert. We didn't want the dessert, so she took off the special pirate's punch drink and child's meal for my youngest daughter. It doesn't include alcohol.
Anyway, the gift card and the free meal made us go with Costco. We thought it was a great deal.