I really enjoyed staying at Kai 's place because of the atmosphere that he created. He is a very welcoming person, smart and intelligent. We laughed a lot and shared our life stories.
The location is really good in Kadikoy: close to the bars/ cafes but quiet enough at night to sleep.
It is the last floor, you should take it into consideration. My days of stay were quite hot and the AC didn't work but there was a window to open.
Kai is a very welcoming and warm person.