The location is fantastic. A few blocks from the beach with a view of the mountains, Ala Wai Boulevard (the river) and a few buildings. An abc store literally around the corner (this came in handy) and 5 minute walk to the local parking garage (The Waikiki Banyon $150 per week).
The building is very old (but so are most buildings on Oahu). Staff were friendly. Directions for check in were easy enough, but security are happy to point you in the right direction. The bed was very comfortable, but also quite high up, (you just about had to jump up to get on it).
TV was ok when it worked. There were no instructions on how to operate it as it used wifi exclusively (which caused the tv to pause regularly due to poor wifi connection) and LG commercials would come on frequently and at the worst time during viewing (eg, mid sentence during a movie or show) (it was an LG tv).
We chose not to use the air conditioner due to a few reasons. It is LOUD. It is one of those old air conditioners you see in the poorer areas of the world sticking out of a window. A red light was always on signifying the filter needed replacing and the front where the air comes out was covered in what could only be described as old mould.
We used the table fan instead (it did an ok job).
The power outlets are not the best (they don't hold appliances in very well, creating an electrical hazard.) I have passed the above points on to the owner for improvement.
There is a full size refrigerator on the balcony (lanai) which came in very hand (though being outside is not the best when you're half asleep in pyjamas and have to open the curtains and door to get to it).
bathroom was clean, but very old. Not being from the US, it took a moment for me to work out how to switch from shower to bath. The shower heads work great, but the bath outlet came on the same time. There was no way of isolating it, and the bath outlet would regularly drip if the faucets were not turned off really tight (even then, it would still have a very slow drip).
The overall stay was comfortable for the most part, though it can get quite loud at night from the locals being ....well......locals (and regular loud motorbikes going past).
I you want somewhere quiet, I would look somewhere else (unless you wear earplugs, that can help drown out some of the noise). You are getting basic accommodation in the heart of Waikiki, so you are essentially paying for the location.
If you want quiet and location, stay in one of the known hotels. Our overall experience was ok, but I think Airbnb has become over-rated.