It's a small but cozy and clean apartment in a great location. In Summer it was a bit hot inside without air conditioner but the apartment is equipped with an individual heating system, so it should be very comfortable to stay there at a colder season. There is a hot water all the time and a very fast wifi.
The neighbourhood of the apartment might be to noisy sometimes, however it is definitely friendly and safe. There is everything you might need around: cafes and restaurants, lots of different small shops and a supermarket, Bosphorus waterfront and a remarkable Yildiz park (maybe my favorite place in the whole Istanbul).