I stayed with Sadik for 7 days in June.
The apartment has an excellent location, walking distance to Istiklal st (<10mins). There are so many great cafes, shops and trendy people in this area. Dalti maya and Van Kavalti Evi for breakfast to name a few and corner stores everywhere. This is a hilly area, great exercise but not for those with disability.
The apartment is 5th floor (5 flights stair) with a lovely view towards Istiklal street. The interior is bright, nicely decorated, lovely plants and lots of character. The room is comfortable, clean and bright with a double bed and small balcony with clothes line. The bathroom is adequate, washing machine available for use. The kitchen is small but also free to use if you like. Sadik has a cleaner who comes 1-2times/week. There is an Istanbul guide and map available for borrowing as well and a transport card as well. Non-smoking.

Sadik himself is a busy man but in his free time he is very friendly, intelligent, relaxed and generous. We had many interesting conversations and he even invited me to join a party with his friends one night and a beautiful breakfast locally. He has some great suggestions for places nearby to eat.
I had a truly wonderful and safe experience staying with Sadik, we will be friends for a long time and I will definitely visit again!