I can't say enough about Sabriya and her home. My friend and I stayed for one week (one in the bedroom, one on the couch which was very comfy) and had a truly wonderful time. The apartment is very central with really convenient connections to public transport all around the city. The flat is spotlessly clean, warm and bright with a large patio for smoking or just relaxing in the sun. Getting to an from the airport is also really easy an inexpensive by shuttle bus.
The real treat of the apartment, however, is Sabriya herself. She is incredibly warm and hospitable. She'll know great places in the area to go to, she knows the city really well. Also do not miss the chance to eat at her restaurant. The food is wonderful, we went back twice. I would absolutely recommend and will definitely be staying with her again if I'm lucky enough to be in Istanbul soon.