I think location wouldn’t have been better than that. It’s worth to say ‘this is real centre ‘ and just step away to everything whatever you need. While your stay, you will be a couple of minutes away from all kind of food, water, change office, Bank Atm’s, metro, tram, bus, attractive events, restaurants, cafe's, antique shops, shops, night clubs, pharmacy, hospital. Most well known Mevlana (Rumi's) house is one-minute distance.
Let me summarize the WALKING distance from flat to following main places;

***Galata Tower ( a few steps away)

*** Istiklal Avenue (3 min) - Tünel - Tram station .
***Taksim Square (20 min) 
***Golden Horn (5 min) 
***Karaköy Metro and Tram (5 min) 
***Spice Bazaar (15 min) 
***Hagia Sophia (20 min) 
***Grand Bazaar (25 min) 
***Galata Bridge (10 min) 
***Sishane Metro Station.(2min)
***Kadıköy Port (Asian Side)- 5 minutes. 
***Public buses station - 4 Mins

***10 mins to Çiçek Pasajı, Balık Pazarı and Demirören.