I stayed at Gonca's place for one month in early 2017, and loved both the apartment and the location. Beşiktaş is well-connected to both Asian and European Istanbul, and the apartment is just a short walk (10-15 minutes) to ferries and buses that head off in every direction. It's also literally right next to Yıldız Park, a wonderful refuge to go on runs and walks, and to sit and relax at one of two late-Ottoman pavilions now renovated and open to the public. The apartment is cozy and full of light on sunny mornings.