We had a very nice stay in this flat.
It's not far from Taksim place, but located in a quiet street so the hassle and the crowd will not bother you. Moreover, the bedrooms are located on the opposite side from the street.
Here you can feel home, there is a nice kitchen and a very cosy living room. Everything was fully functional.
The self check-in instructions were very clear, so even if we arrived a lot later than expected we could, there was no additional stress.