Convenient location as we were using the JR rail. Suburb is actually called Shin-okubo which is one station away from Shinjuku. Walkable to Shinjuku (about 15 min).
Shin-okubo is known as 'korea town'. There were lots of Korean restaurant and a food strip near a large Don Quijote (discount store). Plenty of stores for fruit and quick snacks near the accommodation.
Shower had consistent hot water. Bathroom sink didn't have hot water tap. Toilet didn't have the typical Japanese seat warmer function which would have been good at night when the bathroom was really cold.
Windows didn't block out much of the noise or cold, but we were not bothered by it. Heater in the end room which was strong enough to heat the entire apartment.
Kitchen had basic utensils.
Beds and pillows were comfortable and warm.
Apartment was smaller than the photos make it appear.
Overall, we had a pleasant stay, liked the location of the apartment and the luggage storage provided before and after check out was very handy. Efficient communication via Airbnb messages. Friendly staff who spoke English.