Very very nice stay! I definitely recommend it! Really!
We stayed at Yusuf's place, and we met him, his brother as well as Erol, a very cool guy working with them. They're are all extremely nice, helpful and welcoming hosts.
The appartment is very clean, tidy and comfortable! The Sauna is also very good! It's exactly as it appears in the pictures.
The first night, we were late for the check-in and Yusuf's brother helped us to book the shuttle from the airport. The next day Yusuf gave us plenty of useful indications and good ideas for things to do or places to visit. He recommended also for us a very nice restaurant nearby.
We had many interesting discussions with Yusuf and Erol about politics and history of Turkey, around a warm cup of tea.
The appartment is on the historical center close to all monuments (Blue Mosque, Hagia Sofia, Topkapi palace..). The neighbourhood is very quiet and safe by night. I completely recommend it!