It's a very nice beautiful apartment in the best neighborhood in Istanbul. It is a fully equipped, tidy and quiet place with a nice view of the school square. As many people mentioned before the apartment is full of the owner's stuff, please note that all the drawers are full of dresses and clothes so you won't be able to store your own stuff anywhere but the table in the living room. It was not inconvenient for us as we stayed for 2 days but it could be a problem when it would be a week or more.
Imagine that your friend asked you to stay at his home for a week to watch over the plants while he\she is away. That would be the best description of the place. This place is full of the owner's presence and I would not recommend this place for people who prefer hotel-like apartments made only for guests.
Everyone else would be happy to spend time there!