The studio itself is great: it is accurately described, quite spacious, clean and lovely decorated. Amenities are all new and working.
The location is very hard to beat: historical center that is actually suitable for living (I mean transport connectivity, accessibility for shops, restaurants, galleries, etc...).
The neighborhood does feel safe (speaking from the solo female traveler perspective).
The street is quite lively until late evening, but I still got decent sleep.
Maide is very responsive and easy to communicate.
Overall, I am very happy with my stay in this apartment and it will be my first choice if I visit Istanbul again.