I wouldn't recommend the apartment for a long stay. Maybe for a couple of days, but keep in mind that the neighborhood is not safe. I was traveling alone and it wasn't comfortable to come back to the apartment late evenings. Lately I found out that this district Tarlabasi which I chose because of its closeness to the center is considered as one of the most dangerous place in Istanbul. There is a police station across the road what brings a little comfort though.
Also the apartment doesn't look exactly like on pictures. Starting with different wall colors, ending with dirty floor and walls. Furniture is outdated and the whole apartment needs renovation. There are other rooms in the building and some of them are more renovated than others.