I came to visit Istanbul for the first time with my girlfriend and stayed at Ali's. I would definitely pick the same accommodation next time I come and visit.
Location: Perfect. It is right in the middle of Galata where it is walking distance from touristy Istiklal street, and hip Karakoy cafes and pubs. There are many cafes around, as well as local designer boutiques.
Apartment: Nice, cosy and clean. Well heated (we were there in December) and hot water is plenty.
Hospitality: Ali was extremely helpful. He welcomed us himself when we reached the apartment and stored our luggage in his office after we checked out, before we left for the airport. He was also extremely responsive, and every time we had a question, he answered straight away.
All in all, great experience and I really recommend staying