The room is perfect for longer stays: Kadikoy is just an incredbile place to live. It's vivid and full of shops, bars and restaurants. Very close to the ferry that can take you to the european side. Everything is cheaper and more peaceful on the asian though :)
Two things that are actualle concerning are: no cleaning service (we stayed for 2 months) which can be difficult due to bedsheets changing and lack of detergents (nobody buys a 4 bottles od chemics during that kind of stays) and very poor wi-fi on the second floor. The ground floor wi-fi was ok, but the second floor was horrible: we were asked to connect to other networks, but we really did it all and nothing worked (we had 2 months to figure it out and we are programmers - we really knew how to do that, it didn't work). Not useful for work, but it is ok if you want to scroll IG and so on. We used a phone internet though.
Still: that place is a 5-star rated for us! Gokalp is very communicative and was responding quickly. It was a pleasure to stay there. Highly recommended :)