The house had an amazing Bosphorus view, and the pictures reflect flat's condition. It was clean and well equipped to cook. Also, I worked there, and internet was good enough to maintain a tech job. Owners are responsive, and helpful for the questions.
One thing you should be considered if you don't have a car; there is a very steep slope to reach home that it's not so convenient to walk. Given that finding a taxi is very problematic nowadays in Istanbul, you might have problems to reach the flat. Even some of the taxi drivers rejected to go there as it's too steep.
There is a sweet cat in the flat as mentioned. You should go there if you are okay living with the cat, also while you are sleeping. There are little windows on the doors, that makes the cat enter the room even the door is closed.