I stayed for 2 weeks at Pinar's place. The place was advertised in the photos. Great natural light throughout the day (even in the bathroom!) Internet worked great, with speeds high enough to stream a movie if you just need a night in. The kitchen was well stocked with pans, utensils, plates, etc. I was a little disappointed to not find any v. basic things like salt and pepper. But, there are several grocery stores very close to the apartment, including a great greengrocer just across the street. There are also several little markets and quick eats close by. The market (pazar) on Sunday (Pazar günü) was also great. Amazing olives right outside your door! Along with anything else you might need, but you should prepare yourself for some additional noise on Sunday; and I wouldn't recommend starting or ending your stay on Sunday, because the street is entirely blocked off.
I think this would be a good place to stay for self-sufficient foreign travelers or travelers already familiar with Istanbul/Turkey. The apartment is basic but had good water pressure, hot water, and a pair of washing machines in the basement, which were a true lifesaver if you'll be traveling a lot.