I am not aware of any OV room with a Luau view. I forgot about Ewa Short Wing thank you gmi3804.
Waianae Tower is closer to the parking garage, Ulu Cafe, kids' splash area, walkway to the shopping center across the street (ABC Country Store and Monkeypod), and Rainbow Reef snorkeling.
Ewa Tower is closer to the gift shops, luau, most character greetings, main pool, main lazy river entrances, waterslides, Auntie's Beach House, and most onsite dining options except Ulu Cafe. If day noise is an issue, the waterslide has a lot of screaming, but it closes around 8 PM, with nice tranquil waterfall noises. Ewa Tower faces Four Seasons, a minor hindrance since it's not themed compared to Aulani's strong theming. Sometimes, Four Seasons has loud outdoor gatherings with loud DJ music, which Ewa Tower OV gets the brunt of the noise and interferes with the excellent Aulani loop music or music playing at Olelo Room.