I have rented numerous times from this location. The shuttle has picked me up and dropped me off at various hotels around Waikiki, as well as the cruise ship terminal (not Aloha Tower, but the further one). The shuttle drivers are friendly. At certain times of the day there are more than one, and the wait for the shuttle is less when there are more drivers. You can call and arrange for pick up at a specific time and they have always been prompt.
Sometimes the office can get very crowded in the morning. The vehicles are not great, as they have few and most of the nicer, new cars end up at the airport.
There is actually a new location down the street at the Hilton Hawaiian Village. I think rentals there are more expensive there as the employee told me that the HHV takes a cut.