Communication with Gokce was easy, fast and clear. She gave us explicit directions to the apartment and check-in instructions, so there were no problems with that. The apartment was squeaky clean and had everything we needed (towels, coffee, drinking water, kitchen equipment etc.). It is also spacious and very well decorated, there is a lot of light during daytime.
The apartment is literally in the center of Kadıköy: wherever we wanted to go I took us no more then 10-15 minutes on foot. The ferry terminal is about 15 minutes away so we could reach other parts of the city easily.
Our overall impression of our stay is very positive, we'd definitely recommend staying at Gokce's place!