We got Go Oahu cards, and it did save us a lot of money. To address some potential issues mentioned above - our kids were 7 and 11 during our visit (May/June this year), so no nap to work around. And as to the "how much do you want to plan" question - that will totally depend on individual families. DH went to Oahu as a teenager with a friend and saw very little; the kids and I had never been. We wanted to see as much as possible, knowing a repeat isn't going to happen any time soon. We stayed 8 nights and got the 3 day card. We pre-booked the dolphin encounter at the aquarium and the catamaran tour but otherwise booking wasn't necessary for anything else we did (on the card; we did reserve Arizona times but that obv had nothing to do with the card). We did purposefully do two things per day for maximum savings, but to be honest - we would have done that anyway b/c traffic sucks and if you're going all the way to the other side of the island, you might as well make it worth your effort. There is NO WAY we ever would have paid for the dolphin encounter, which is crazy expensive and I saw no discounts offered elsewhere. Otherwise, it was covering things we would have done anyway, and saved us money doing so. If you don't want to do more than 1 thing per day - not a wise purchase. However, I would also advise you not to plan to do like 7 things all over the island on 7 separate days b/c the traffic will make you crazy. Ultimately, I'm very glad we got it and saved the money. I have zero regrets. Would I get it again? Probably not - b/c if we go to Oahu again, it'll be for purely Aulani amidst island hopping... we saw pretty much everything we wanted to already. I can link to my trip wrap-up post if you are interested in what I used it for. Just let me know and I'll dig it up.