The apartment is conveniently close to Higashi-Shinjuku station so it's easy to get to anywhere from there. Also easily walkable to Shinjuku and Kabukichō. The building is a little old and drab, but the apartment itself is modern inside.
As the title suggests it's more suited for solo travelers, as the adjacent buildings aren't very family friendly. If you're planning to have a busy schedule out and about then this apartment is a good place to rest after a big day.