We had a great stay at Vefa's place. It is centrally located (about 10 minutes' walk from Blue Mosque, Topkapi Palace, Hagia Sophia), walkable to other mosques, tons of restaurants, cafes, supermarkets, as well as close to the tram, which you can easily navigate to further sites. The place is clean and the beds are comfortable. Also, Vefa is very communicative. He responds almost immediately to messages and WhatsApp. He arranged our airport transfers, advised us on money exchange, arranged our COVID tests (a technician came to us at the apartment, very easy) and arranged taxi rides to other places we wanted to visit. Highly recommend.