Cüneyt is a very helpful guy and was available when I needed help with the door's lock. The location of the place is excellent, because the Karaköy area has many very cool, little cafes and things, and it's right by a tram station. (Just bring ear plugs, because it is a busy area.) The apartment itself needs some TLC and attention to details, because it does feel a little run down (including the mattress). If you book with that in mind, it's a great spot to stay in during an Istanbul visit.