The apartment is small (but in Tokyo standards it s just average). The building and the furniture are old and shabby (It is difficult to keep it clean precisely because of that). The host is very responsive and acted quite quickly to resolve any issues that occurred while we were there. There is a children’s playground nearby so I guess that people traveling with children could find it convenient.
In general, Otsuka is not a good spot for tourists or business (unless you have a specific place of interest in mind). However the Yamanote line is convenient and the station is just 8/10 mi utes on foot.