Everything was just great. Muge and Nebi were very welcoming, explained everything about the house, transport and neighbourhood, and let us leave our luggage before check-in time (we arrived early in the morning). The flat is clean and tidy, and has everything necessary for living. One evening we had problem with internet, but our hosts solved it immediately.
We were five, and we had enough room.
The neighbourhood is quiet and safe, and close to Taksim. From one window you can see a little bit of Golden Horn, and there is a mosque on the other side of the building. There are a lot of grocery shops around.
Muge and Nebi, thank you!