The appartement of Josephine is quite convenient,especially for those going to the convention center (8min walking). Waikiki beaches are close too, but frankly that is not the best part of the island. My recommendation is Waimanalo/Sherwood beach. Gorgeous. Reachable by bus (1hr) or car (40 min) scenic road too.
Bed was comfortable, fridge new and handy. AC a bit noisy, but you can turn it off to sleep as it's cooling down at night. Ala Wai is noisy, but can offer you some unexpected entertainment (car accidents). It's also the only place where you can park for free. A few other spots in streets parallel to Niu for the night. Otherwise the building parking is $40/night. Ouch. Ala Moana Center is also a good place to park during the day (10min walk) and satisfy any shopping crave. If you're sensitive to light, oversleeping in the morning will be difficult as the curtains can't hold the bright light coming from outside. The view (17th floor) is very enjoyable with varying lights. Did not try the pool nor the gym. Elevators where not working full force which made some waits a bit long. Overall a great stay that I would start over without hesitation, if I did not have to go back to Europe.... Josephine was very responsive (and busy). Instructions were clear, the apartment was well equipped with plenty of first need products (shampoo, towels, sugar, coffee,...) which is appreciable when you arrive late at night.