Flat is pretty nice. Halil was exteremely helpful and quick in helping for anything needed. We needed better internet connection than there is, and he arranged a cabled connection right away. He also took care of our laundry even if there wasn't a washing machine in the flat.
Location is great for anyone who wants to be at absolute center. You are basically one street away from Istiklal Street which is the most touristic place in the city. But it also comes with its downsides. There was music until 6 am that made it quite difficult to sleep on friday and saturday nights. Flat is at 5th floor so this could be problem for some people too, we didn't really mind.
Furnitures were kinda old and stove was not really suitable for cooking so we had to order food everyday. Overall I recommend the place, and thank to Halil for good hospitality.