Time for a perfectly honest review ...
Good points: Room was clean and bed was comfortable. Location was central to the area of Beyoğlu. Atacan (the acual physical host) was friendly and helpful.
Bad points: Room needs blackout blinds as there is a street light right outside the window and other windows from across street can see in. Room had no running water at times. I understand that Turkey suffers from water issues but this needs to be made apparent in the advert for people paying to stay there. Street is noisy at night well until midnight (mostly children screaming). Street does look very run down and smells like fish. You'll probably be venturing into the centre so you may be able to look past this. TV doesn't work. Check-in could be improved by telling us the actual number of the house. Based on this, I feel the price should be significantly lowered.