The flat is a hidden gem in the very centre of Istanbul. It is a spacious freshly renovated place with high ceilings. The kitchen is also very well-equipped.
Mami is one of the most welcoming hosts I've met - he helped us to arrange a transfer from the airport for a moderate price, and he fixed all the issues that were coming our way real quick. I could not recommend enough staying at his place for the trips to Istanbul of any length.