We stayed there for 6 days and had pleasant stay. It was just like what we expected although after a couple days we found the mattresses were somewhat thin and a bit uncomfortable.
The highlight is the location. It's very near to the elevator exit B3 of Higashi Shinjuku station, about 5-7 minutes walk to the platform, which was important for us who used pram everyday. The station itself is less crowded and serving 2 lines that can take you to places of interest. They also provided complimentary breakfast at their Domo Cafe, 15 minutes walk toward Shin Okubo station which we perused once. Simple but good food and coffee. The team was also very responsive and accommodating. Recommended airbnb!