I ll repeat what the visitors said below. The designers apartment with the really nice window view of the Anglican Church. The location is great!
The museum Ayasofya can be easily reached within a 40-minute walk, Galata tower - 5 min, the museum of contemporary art - 10 min, metro Sasene - 4 min ( and 40 min to airport Atatürk), restaurant for breakfast with Bosporus view "Midpoint" - 10 min;
Restaurant for lunch with excellent cuisine and amazing panorama - "Divan brasserie" - 15 min;
Restaurant with romantic and lounge atmosphere for dinner "Latera" - 15 min;
The oldest shop with turkish pastries Karaköy Güllüoğlu - 20 min.
The apartment is located in the old building and you should be prepared for every noise from adjacent apartments is audible, but its not problem because you are in the center of Byzantine empire! Its really cool!