Hello, my friend Julia stayed there, and thats what she said:
The apartment is clean and bright, 200 meters from Istiklal - so it is a little bit noisy.
There were some problems with heating and hot water (but that was due to the breakage in the central system of Istanbul - so it was fixed quickly).
Please pay attention that all the drinks and snacks will be charged separately.
The host is very nice and responsive, will help to solve any kind of problems.
Good for a short stay for tourists, if you are in Istanbul for a long term it's better to find something far away from touristic place.