I stayed with my friend in Mummer’s place and I have to say it is really comfortable and clean. It is exactly as shown in the pictures and we did not face any difficulties getting there as he provided the location and met us near the place when we arrived.
The location is really good as there are a lot of places to go nearby (Galatea tower and Taqsim road) and the metro station is literally few minutes away which means you can go around Istanbul easily.
Muammer is quite helpful when needed which is really appreciated.
:)