Would like to start by saying that Yusuf is an amazing host. So kind, helpful, and accommodating. Wrote us on Whatsapp before we even came to Turkey to ask us if we needed anything and to give us recommendations for places to visit/travel.
The apartment itself was located in the best part of Old Istanbul. We were less than a 5 minute walk from amazing restaurants and bars, and less than a 10 minute walk from the square, where you can see the Blue Mosque, Hagia Sophia, and Top Kapi Palace. We stayed for a week and saw all of the major attractions either on foot or a short ride on the tramway (15 Turkish Lira for a day ticket, less than $1).
The apartment had everything you need, it was clean, and perfect for our stay. Would recommend it to anyone staying in Istanbul.