We were lucky being here ;-)
The flat: clean, comfortable beds, absolutely ok for 4 persons, everything you need is there, the terrace has amazing view and made us happy. Be aware, it's on the 6 floor and there are stairs.
The area: Galata is just there; coffee and great breakfast/ restorants, shops. Same time the apartment is on a very silent street. Most of the sightseeing you can reach by metro or by taxi for low cost.
Communication: Ayla respond us rapidly and gave us always useful advices. She is a nice person and we are very thankful to her.
Dear Ayla, next time we will visit you again!