We stayed twice at Yuka's during our two weeks in Japan and loved the experience both times!
The apartment is just the way you see it in the pictures, perfect for two people, cute and with everything you may need during your stay at Tokyo. It's true that is located just beside the highway, and while I understand how the background noise can bother some, we didn't have any issues with it or to be able to sleep.
The location of the apartment is also really convenient, just 3 minutes away from the Keio Line and in a 20 minutes walking distance from the Shinjuku station. There are many nice restaurants located nearby as well as convenience stores.
As a host, the team that manages the apartment was always really fast answering our questions and making things easy for us.
I wouldn't hesitate to stay here if I ever come back to Tokyo! :)