The cozy apartment in a great location. Looks the same as in the pictures. It has everything needed and even more: like a boiler with drinking water or a power adapter for the international sockets.
The owner is really helpful, provides guests with portable wifi and local tips. He helped us on every occasion. The location is near the old center, a walking distance to the most touristic spots and near the Metro station.
The only one minus I can recall is that Istanbul is the city of cats, and most of the old streets have this specific cat's odor.
The stay was great, recommend.
P.S. We were visiting Istambul in March, and it was a bit chilly. So don't forget to take warm clothing if you are arriving at this time of the year.