I was traveling alone and stayed for almost 3 weeks while working at home, and I can say I felt very comfortable in this place.
First of all, Anas is a great host, he was very attentive and responsive, he really cares about his guests! He responded very quickly to any question, and if there was any issue he resolved it very timely and he even added an extra table to the kitchen when I asked.
The apartment is cosy though not much space, for me it was enough even though I spent much time there working, for two person - maybe for short time. It has all necessary equipment. Internet was mostly stable and good enough to work online, just a few interruptions happened but quickly resolved.
It was interesting experience to stay in Fatih district. There are not many tourists and local people mostly prefer modest clothes, not many people around understand English. However, as a lone european woman I felt completely safe there, I haven't faced any problem (even compared to some touristic areas where you may face some unwanted attention). There is a local market in 5 min walk with various restaurants and small stores, you don't need to go to Grand Bazaar to buy sweets and everything. I would especially recommend AlRaii (arabic restaurant) and Malta Firini (bakery and desserts). Also every Wednesday there is a weekly bazaar right under the window, which is definitely worth seeing!