We made reservations for 4 excursions on the first 4 days of our 7 day trip:
1st day: All Day Oahu Tour
2nd day: Luau and show at the Polynesian Cultural Center and entry to the Cultural Center before the dinner to walk around etc...
3rd day: Jungle Movie Tour at Koaloa Ranch
4th day: Tour of Pearl Harbor (includes admission to USS Arizona, Battleship Missouri, Aviation Museum, USS Bowfin Submarine)
The rest we are gonna take by ear when we get there. Only 4 reservations so we get to relax that last days at Aulani and dont have too much planned so no crazy running around to a million things every day. So for us this Oahu card more than pays for itself for the places we are gonna see above and if we decide at the last minute to get up and do another item on the list of things we can do with the card we can do it without worrying about the money. If you dont try to do everything on the card choices or plan everything for the last part of your trip then you are fine in my opinion.