We stayed one month in Katharina's apartment and we absolutely loved it. It is so stylish and comfortable. It has everything you need, it is a real home. It also has an amazing location, the neighborhood is vibrant and you can find all you need within walking distance, stores, supermarkets, restaurants,etc. It's a 5 minute walk to the metro or you can take the bus to the metro. With an Istanbul kart card it's so easy to get to Sultanahmed and other touristic areas of the city. Katharina was also really helpful giving us tips of best supermarket in the neighborhood and the bets hair and nail salon. Nick her contact in town was also very helpful and they were both extremely responsive answering very quickly to all our messages.we would definitely recommend staying here in istanbul. Only downside is that since it's so centrally located in Nişantaşı you can hear the traffic from the street and noise from the school behind the building but if you don't have a noise sensitive, everything else is perfect!