We were two personnes, we booked in the 17th of july and spent one week at the flat.
we were welcomed by ahmet the friend of Taner, he was was very humble and very helpful. The flat was surrounded by markets, bakery shop... you can walk from 15 to 20 min to arrive to the taksim square as for the Istiklal street it will take from 5 to 10 min or you can just take the bus that will leave you at the taksim metro station 5 min away from the flat.
We feel like we were at home. It was very clean, perfectly decorated with the stuff for the kitchenette. there was always hot water and electricity. I would definitely recommend it!