My two high school daughters and I stayed here for 5 days doing college tours/visits (e.g., NYU, Fordham, Columbia, etc.). They slept in the bedroom (large bed ... maybe king size?) and I slept in the living room. There was a "click-clack" sofa/bed in there, which I covered with an extra futon the host provided and I was very comfortable. The "living room" has its own doors and curtains to make it like a private room unto itself. The two rooms are separated by a hallway with a kitchen and a bathroom, so each room can remain undisturbed while people either use the kitchen or bathroom.
Both rooms had big screen TVs with Netflix, Amazon, YouTube, etc. There was plenty of heat in each room. The kitchen was well-stocked with all kinds of pans and spices/cooking oil, etc., and there was a dishwasher. The bathroom shower was powerful and hot. There was also a washer/dryer, but we didn't use it (but I'm sure that would be a fantastic amenity). The building was secure. I think each "floor" was a separate private residence. You do have to ascend 3 flights of stairs to get to the top (the rental residence). We did not find that a problem at all. In fact, if you stairs-averse, then you are not going to like Manhattan, because it is a walking culture (to the subways, up and down stairs in the subways, walking throughout Central Park).
The neighborhood was nice (I think this is probably one of the nicer neighborhoods in Manhattan ... known as the "Upper East Side"). It seemed quite safe to us. In fact, I felt everywhere we went was quite safe. There are pedestrians everywhere (i.e., you are never alone), and these pedestrians generally consist of "regular" people -- mothers pushing their strollers, children walking to school, business people, little old ladies, and then an occasional "homeless" person sprinkled in there. There were restaurants everywhere, from cheap pizza to expensive sushi.
The subway stations are nearby (3-block, 10-min walk). There are metro card machines in each station. We each bought a 7-day metro card with unlimited rides, and it cost $34. Then, we rode the subways all over town to the different colleges and other places of interest. It was, in my opinion, very simple to understand and figure out. Manhattan is a thin strip of an island, only 2 miles wide and about 10 miles long, and Central Park takes up half the space. You are generally only going north ("Uptown") or south ("Downtown"). The streets are laid out in a grid by numbers. So, the rental is on 73rd Street. You might take the subway down to "Grand Central Station," which is, I believe, 42nd Street.
What else can I mention? Central Park is 2 blocks west of the rental, so a very quick walk. We are super happy that we stayed in this "home" rather than a hotel. The owner was great, and he owns a business on the bottom floor, so he is always around and available.
We recommend.