We had a very good stay at Seyid's place. He is a very good host: hospitable, responsive and caring. He offered advise on local restaurants, stores, etc., and was always there to answer any question we had via WhatsApp.
The flat is excellent for 4 people and could accommodate up to 6, I believe. It has mostly everything one would need for a comfortable stay. It is on the second floor and reachable through steep narrow stairs, so for people with mobility challenges this might not be the right fit.
Location is very good, near the Little Hagia Sophia, 7-10 minutes walk to the Hippodrome (uphill).