We have stayed at the place for 10 days. What we liked:
1) the hosts (Uğur and Gamze) were extremely nice and communicative
2) Bekistas is one of the best districts in Istanbul, quiet residentian area with nice architecture yet close to the city center
3) the living room has amazing view
4) the weather was really bad during our stay, but the apartment was well heated
What was not that good:
1) the apartment is quite old, so not everything worked properly (leaky sink, not closing doors etc)
2) the hosts smoke in the apartment so it took quite some time before the smell qot less disturbing
All in all, we had a nice stay) Thank you, guys!