Great airbnb experience, we are lucky to find this place for our one week stay in Istanbul.
Smooth and flexible check in and check out. Cozy, big and well designed apartment with 2 bedrooms and a small balcony with an open and beautiful view to the old side of Istanbul. Apartment is bright, neat, well isolated and has high ceilings (i guess 4m). We were first week of May, and it was bit coldish though, weather-like as well as in the apartment, so make sure to have a warm clothing just in case.
It is well equipped, especially kitchen with all the plates, dishes and utensils included. Matrasses are firm and comfortable for a good sleep.
Regarding emplacement, it is indeed conveniently located : in 10 min by walk there is the most popular and vibrant Istiklal street, in 15 min Taksim square (there is a shuttle busses station to reach Istanbul airport, commutes quite frequently (i think every 30 min) and costs 52 TL/person, it takes about 30min-1h to reach the airport depending on the traffic (in case you need it: it is in front of 'Point Hotel Taksim').
There are a number of small shops around the house, one being just downstairs.
To be honest, I have had a bit of culture shock right in the beginning walking through the neighboring areas (especially main Tarlabashi street), but it all got vented out once you got to know the area, area is indeed safe and you can bump into foreigners quite often. People in the neighborhood were very nice people, comprehensive and helpful.
I hope i haven't missed any important points i wanted to mention. If so, just ask Bercin, she is fluent in english and an excellent host:)