First about the place:
1, location, almost perfect location, downtown Waikiki, a lot of good grocery stores, beach supplies stores, restaurants and Waikiki beach within distance of three blocks.
2, room itself, spacious 1B1B, all necessary furnitures, very clean and comfortable, similar as hotels.
3, view, it's in high floors, so got spectacular view, both mountain view and partial ocean view from the lanai.
4, amenities, great pool in the building, big and heated, we actually spent a lot of time there; all kinds of beach and snorkeling equipment, beach towels, chairs, etc; assigned parking spot in the building.
Then about check in and out, simple and smooth, you won't need to worry about it!
About our host, a super nice lady, thank you for your help, Tiare!