You really need to plan out your schedule in advance and make reservations well in advance in order to maximize this card. Most things close early so it's really only possible to do 2 a day. Not sure I would choose this option again. While we might have saved money, I think I might have preferred to spend a bit more to get higher quality events and have a better schedule.
We purchased two of the 7 day passes for 285 each. I did my research and made a schedule of the things we were going to do each day. We did nearly everything that interested us on the card and saved 368 per person. You need to make a schedule prior to purchasing the card to make sure what you want to do will save you money. If you just buy the card and aren't organized you will end up missing many activities and not getting your money's worth out of the card.
We just returned from Oahu, and purchased the 7 day card for our family of 5. Overall, the Go Oahu cards were great! Gave us a large variety of activities to pick from which was great. Just be aware that if traveling the Christmas to new year period, as we did, a lot of the really popular activities were already fully booked which meant we missed out, so would suggest to book the your activities in advance if you don't want to miss out on something. That said, we still had heaps of other choices to work with. Booking process was really easy with the information book with all contact numbers provided. Just be aware, transportation on activities is not included, so this is an extra cost. As we didn't have a hire car for our week there, all the activities we chose did provide a shuttle service as a reasonable price which was great as we didn't then have to sort out how to get to venues on the other side of the island. Overall really happy with the Go Oahu card with the value for money for our family of 5.