This is definitely the DREAM stay!
First of all Birim is a great host. Very attentive, and responsive to every question I had. The location can't get more central than this, it's right in the heart of the European side of Istanbul. Super close to every major transportation. The apartment is just as stated "An artist's apartment". Full of wonderful paintings, and art pieces. It really makes you feel like you're living an artists life yourself. I would 100% recommend this place to everyone traveling to Istanbul. A+++