1. Crispy clean flat - very important if you are like me travelling with three kids
2. Very helpful staff and host. We checked in at night and checked out at 4 am - still was nice and friendly. Gave advice on great breakfast location and supermarket store. should have asked him more questions in advance to make my travel in Istanbul even better.
3. Location - walking distance up to hill to the closest tram station. If you prefer to go to Sultanahmet by walk - quite a walk in hot and humid Istanbul in August, but still nice and worth doing at least once. A lot of places to eat nearby.
4. Overall impression - nice comfortable flat with everything we needed, including life saving AC and washing machine. Yet some stuff need to be fixed - like shower door (works, but need a bit of care when opened). Hope that at the low season (wonder if there any) it will be fixed.