I and my family stayed in this apartment for more than one week. You can have access to Isik very easily by phone and he is a nice guy and really helpful.
This place is 2 min far from Taksim Sq. Super easy to catch taxi and go around.
The surrounded region is full of suites and small hotels which some people may don't like its atmosphere. Isik told us to don't use tap-water for drinking and he was regularly providing us 10L mineral waters.
The apartment inside was clean but do not expect as shiny as photos.
The apartment is in third floor, without elevator (which is already mentioned in airbnb page ). So if you have serious problem with stairs (like old people) consider this issue. Due to some technical problems on the area, we experienced 2times running-water cut (that was a problem in whole area so not a negative point for apartment) and Isik really helped us to have less problem.