I spent a week at Can's place. Everything is as pictured, the room was nice and quiet, the bed comfortable, both the room and the shared spaces were clean.
The location is also very good, ten minutes by foot to the Taksim stop of the Havaist airport shuttle, fifteen minutes to Taksim square and the end of İstiklal caddesi. It is also quite easy to find. Just keep in mind that Istanbul is built on hills, so practically nowhere is flat, including the street Can lives on. :)
There are several supermarkets, grocery stores and restaurants nearby.
My schedule didn't really overlap with Can's so we rarely met, but he was ready to help and repeatedly checked whether I needed anything. He was also always quick to reply to my messages both before and during my stay.
I would definitely recommend his place to anyone and would stay there again.