Gürhan is a really nice guy, who is answering really quick if you have some questions or needs. The flat is pretty much what you see is what you get. The roof is a little thin so you can hear the birds pretty loud. There is no window in the bathroom, but it was not a big deal for us - just opened the door and the balcony door and it was alright. The shower is pretty nice.
The location is good, you have everything you need around the corner and can go anywhere with bus or metro. Also the havabus(airportbus) is like 10min walk away.
I as a software developer had sometimes a little problem with the internet but for casual use it should be fine. Also there are European styled coffeeshops ~7m walk distance away where I had good coffee and solid Wi-Fi.
All in all I can confidently say we would book the flat again.