We had a great stay!
The flat was clean and the the communication with Ilkan was easy. He answered quickly and managed our requests. The Kitchen has everything important, but you don't really cook in Istanbul. Food is too good and supermarkets are not. The interior isn't new but works out well, it felt cosy.
The location is unbeatable, we stayed over a weekend and had no noisy surprises from outside. The bed however is squeaky.
The rooftop has a lot of potential but we couldn't use it since the weather wasn't good enough.