Me and my family stayed at Yakup’s place for one week and we loved this place and the area. We were 7 people, the apartment is big and there is lots of space, the beds and sofa beds are very comfortable. The apartment is very clean, bright and it has elevator which was important for me given that I was traveling with my parents who are early 70s and my nephew (5 years old) . The location of the apartment is perfect; it is 5 min to Taksim square and Istiklal St. Also by walking for 15 minutes you get to the T1 that takes you to the touristic area like Sultan Ahmed Mosque etc. There are lots of supermarkets and bakeries close to the apartment in 2-3 min walking distance.
Yakup himself was such a great, welcoming host. He was reachable and would respond quickly to questions/requests. His friend Yousof who greeted us on the fist day was also very nice and helpful. He walked me around the area and showed me the neighbourhood and he helped with the luggages on both our arrival and departure date. They both would do everything they can to ensure you have a comfortable and enjoyable stay at their place. I highly recommend Yakup's place to everyone and will definitely stay again here.
The only concern I had before booking this place was the steep street on the way to Taksim which turned out to be okay for my parents, it was manageable with walking slowly and with cautious (be aware if you are traveling with people with knee and back issues, though I should say everywhere in Istanbul is like this). Also check with Yakup about a construction that was going on if you are planing to spend more time in the apartment, it didn't bother us as we were outside most of the time.
Thanks again Yakup and Yousof for making our stay in Istanbul such a memorable one.