My sister and I stayed for a week at this apartment. Oktay was a great host! The communication with him was very easy and he was resposive at all times for any kind of inquiries. He even offered to organize transfer from/to the airport which worked well even in the ealiest of hours.
The apartment was clean, really cozy and was equipped with everything you might need. The location is amazing and allows you to explore the city by foot for a big part if you wish. There are lots of restaurants around as well as public transport.
The area around Galata Tower gets extremely busy and the prayer call can be heard very well at the apartment (otherwise it was quiet in the apartment). For us that was no problem though.
We would recommend a stay at this apartment to everyone. :)