Isak's flat is wonderful. The location is perfect, walk up the hill and you're on Istiklal Caddesi, walk down and you're in Karakoy which is full of great cafes and art galleries.
The flat itself is lovely, and the bed, although small, it super comfortable. Its clean, the bathroom is huge, and every room gets loads of light and has great views.
It was perfect for our second stay in Istanbul and we highly recommend staying here.