We stayed in this apartment for two months. It's in a great location, very close to Central Park and in walking distance to the Met, the Lincoln Center, lots of great restaurants, and even Times Square if you feel like making a bit of a hike. It's also dangerously close to Levain Bakery (go early to avoid lineups!). Riverside Park is half a block away, and is a gorgeous, relatively uncrowded spot for walking or running. The apartment is close to the subway, for longer jaunts. The apartment is extremely quiet, very good for getting work done, and set up so that two people could have their own workspaces. Mariko and Krishna are extremely responsive hosts, very fast to answer any questions or to get any issues taken care of.
This apartment would be well-suited to shorter stays. Since the photos were taken, the sofa-bed has been removed and replaced with a single bed. As a result, there is nowhere to sit except on a bed. The kitchen, while fine for making breakfasts and lunches, is minimally equipped. Wifi is inconsistent. The entire building could use some TLC. If you are going to be exploring the city most of the time, these things will probably not be an issue. On balance, for us the great location and the quietness of the apartment compensate for its challenges.