Ufuk is a good person. He took care of us well. The internet was fast enough. The flat was very nice and wide. Only the location can be open to discussion BC it takes 20 min by walking to the metro station and Cevahir Mall. The roads are a bit hard to walk bc of the uphill. But under Istanbul conditions, these are very tolerable things considering the quite, calm and safe streets.
For a small help: The apartment is near Dora Hospital (To search on map). Taxi takes only 10 TL to the metro station in the mall (Never ever pay more than 10 TL) You can take taxi in front of Dora Hospital.
Thanks again Mr. Ufuk for everything. It was a good time staying at the flat. It felt like home :)