I would like to start by saying that by far this has been my most comfortable stay in Tokyo. Not even considering the location, Min and Haru's place is extremely clean, well stocked, and just nice to be in. There is a reason why that have basically a perfect rating on Airbnb as hosts.
You stay in a perfect location in Shinjuku; it is within a 10 minute walk to Shin-Okubo station, and 15 minutes walk from Shinjuku Station and Nichome. Not to mention the walk to Shin-Okubo is full of places to eat, from korean street food to a proper sitdown meal.
The apartment itself is full of life. From the moment you walk in, you can tell that this isn't some throwaway location from a landlord that has 500 other places in Tokyo. The walls are covered in hinoki wooden panelling, the owner posts their custom painted gundam figurines everywhere. The common room has a great view of the street and is stocked with everything you'll need for your stay. You can even go up to the roof and look around at night to relax. You are on the 9/10th floor, so you won't be woken up by people stumbling around in the street after midnight.
Most rooms you will stay in have a huge window that looks out onto the street, but from high up. It's beautiful in both the morning and at night.
As for amenities, you have access to a washer, a bath/shower, two bathrooms, a fully stocked kitchen with fridge, and balconies to smoke. You share these with the other guests, which I never had a problem with.
I know this is a long review but to conclude: If I have a choice I will try and stay at this place every time I come to Tokyo. The price is reasonable, the location is fantastic, public transport is close-ish and easy to access, and the apartment is comfortable and beautiful. You won't regret staying here.