TLDR: windows don't close completely + popular street = loud and smelly all night
The windows on the apartment are not going to keep much out of the apartment, and with that comes our biggest problem with our stay. We booked with the hopes of a room to stay the two nights in Waikiki but were quite displeased with the lack of ability to fully close the windows and thus lack of sleep. They are essentially glass slats that close/open like shutters but because of that they do not seal. This coupled with the large amount of vehicles and pedestrians (often drinking and talking loudly, or worst smoking cigarettes or marijuana) made for plenty of noises and smells all night as it's seemingly a very popular street to go down.
I would hesitate to recommend this to anyone who is not a very heavy sleeper and doesn't mind hearing/smelling whatever is going on outside the window as you won't have much choice.
The room and amenities were fine and on par with the asking price but the above made for a very unpleasant sleep experience.