Azadeh's apartment is charming and really historical. When you enter the apartment you feel the beauty of Turkey from the last century. It's like you visit the house of your grandmother, but the Turkish one.
I stayed here for a few days with my boyfriend and another couple. We planned to work remotely during the day and walk around the city in the evening. We really enjoy our stay, because the apartment has a lot of rooms and 4 people don't bother each other, and cool places like bars, coffeeshops, cafes and attractions are really close to the apartment. In my opinion, Chihangir is the best location for a tourist, who arrives to Istanbul not for the first time and wants to feel how Turkish people live, because this place has really small amount of tourists. There are also a lot of antique shops, galleries, streets with hand made shops, and people in the distcrict speak English very well.
The internet was fine, but sometimes it dissappeared for 5-10 minutes in the evening, which was not really important for us. The rest of the time we did Zoom calls without any problems. The shower worked very well, there was hot and cold water. The heating is not central, but you can change it anytime and the temperature inside the apartment was very comfortable.
But I need to warn you, that outside the bedrooms it might be noisy, sometimes people stay in front of the windows and speak loudly during the night. I used ear plugs and heared nothing, but If you are sensitive to noise and don't use ear plugs, this apartment is not a good option for you. During the daytime the noise from the outside did not bother us from work.
And the last point, that I misread the description and there are only one bedroom available and another room has couch, so the rooms are not equal and you should understand that if you arrive with two couples. Anyway, I slept in the room with the couch and it was small but cozy.
To conclude, I do recommend Azadeh's apartment. This place is very nice for a short stay and for active people.