Gorgeous apartment, just as described, even better than the photos, far above the city noise, which I love because Istanbul can be very loud. On top of that Zeynep was a fabulous host.
The location is of course a bit off the map for the typical tourist route, but if you want to explore the "asian" Istanbul beyond Kadiköy, which features only few such luxury buildings, this is good starting point (further up on the main street, 5 min. walk, you can catch a bus every few minutes or even less to Kadiköy, which takes only 10-15 min. to get there)
There is the wonderful marina only 15 min. by foot, where you have a bike path (you can also rent bikes) and a even a padded running path and restaurants with gorgeous seaside views. I have not tried it, but the bike path seems to continue all the way to Pendik with its longs sand beaches, which is more than 20km. The neighborhood, Göztepe, is middle class to the north, where the apartment is located. It looks like at least a third or so of the buildings in the vincinity are new and high-rises. When you walk towards the marina, the neighborhood becomes upper-middle class to rich, with fancy stores and restaurants to the east on Bagdad Cadessi.
For people relying on high-speed internet, the connection could be slow and patchy at times, but that seems to be rather common for Istanbul.
I had a great time and would come again any time!