i will definitely stay again at istanberry on my future business trips to Istanbul. The apartment was clean and pleasant to stay in.
Please note if you're a light sleeper, the walls are very thin. Also, the Beyoğlu district is a working class neighborhood which took me a couple of days to adjust to, because of culture shock. But its walking distance to Istiklal street is amazing.
The guys in the 24/7 office will go above and beyond for you.