We found all the conditions we need in this apartments.
Clean apartments (5th floor) with 2 bedrooms, newly renovated, excellent Wi-Fi, just fantastic views to the Marble Sea, Sokollu Paşa Mosque (architect Sinan) and the Little Hagia Sophia Mosque, 5 minutes walk to tram stop T1 Çemberlitaş and 10-12 minutes to Sultanahmet, 5-7 minutes to mini markets Şok and Migros Jet.
Enough safe area (you can meet beggars from Syria, but they are everywhere in Istanbul).
A very helpful host (he has a restaurant business next to apartment) and a very polite son, ready to help in any way.
The host is always available and immediately responds to requests.
Further positive points:
1. You can eat at the host’s restaurant until 2 a.m.;
2. The best currency exchange office in this area Atlas Döviz (Grand Bazaar) is a 10-12 minute walk from the apartments;
3. It is easy to get to the apartments at HAVAIST 12 from airport IST.
About the possible improvements of the service I have informed the host.