We stayed a week at Yasuhiko's apartment.
It is fantastically located, a couple blocks from the beach and easy walking distance to almost everything in Waikiki. The apartment was spacious enough for two adults, clean, and comfortable. The apartment has a great balcony with a pretty good view of the beach and of the sunsets - a great place to have a meal or drink if you want. There is a big closet with plenty of hangers and some shelves for your clothes.
The building amenities include a pool and hot tub, as well as a coffee shop and mini-mart for essentials. Key benefit is parking if you're renting a car - parking is extremely difficult in this area, and Yasuhiko makes it easy by providing a parking permit for the parking garage. Do note that your spot is not reserved, and it might get a little busy entering during peak hours.
Yasuhiko was very easy to communicate with. Very detailed information of check-in and check-out procedures are provided, and any other questions are answered pretty quickly.
I would recommend Yasuhiko's place if you're considering visiting Waikiki.