This was our second times staying at Hikmet's apartment. During our stay, Hikmet and his team were very helpful. Since the first time we arrived, we were helped with our luggage, directions, taxis, place to go, etc.
The roads surrounding area were quite narrow, up and down the hill but it's quite close to tourist place (Hagia Sohia, Topkapi Museum, Grand Bazaar, tram station, restaurants, mini markets, etc). You can call him if need direction to go to his apartment.
There is a nice mosque just beside the apartment (Sokullu Mehmed Pasa Mosque).