Elif's place is only a 3-5 minute walk from the Hagia Sophia. It's set aside from the main tourist area so that it is nice and quiet at night. The exterior is not much to look at. A matter of fact it's not pretty at all. Despite outwards apperances, the rooms are very clean and neat. You have the essentials such as a small safe, refrigerator, your own bathroom, etc. It's pretty much a mini-hotel with a 24 hour concierge.
The bathroom shower has decent pressure. Shower temperature fluctuates a little, but not so much that it is overly annoying. Beds are comfortable and clean.
Breakfast is complimentary and offers a nice variety of foods. My favorite was the egg crepes (they called them pancakes), which included over 8 varieties of jam (rose, orange, fig, quince, apricot, etc), as well as Nutella and honey. The breakfast area is on the roof in a covered terrace providing you some views of the Bosphorus Strait.
Note that there is no lift on the premises and there is a lot of stairs to reach the breakfast area and some of the rooms. The stairs can be quite steep with some sections having a low ceiling (watch your head).
Overall I highly recommend this place for the economical price, cleanliness, location, and nice complementary breakfast!