I leave for AUlani in 9 day and am still trying to figure this out. In most threads I have seem , the general consensus is to rent a car but we are not
DVC members and only planning to rent a car for a day to tour so the $35 parking fees aren't worth it to us.
Right now in my research it seems to the best option depends on the amount of people in your party. If you are 3 and under, a shuttle seems to be the way to go. Aulani recommends Speedishuttle. I have seen other companies and all their rates seem to be around the same unless I am missing something. If you are a family of 4 like us, a Taxi with a fixed rate seems to be the best bet. the one recommended both by AUlani and on here is Charley's Taxi which has a one way flat rate of $55. I saw another one today "Star taxi" that charge $50. Has anyone used them? I am pretty sure we will just go with Charley due to the recommendations.
I can't help with families larger than 4 though. Sorry. this is just from my research.