I have mixed feelings about the stay:
Host was great and ready to help, the location is great - everything you need is near - cafes, grocery shops, Besiktas ferry, bus stops. Also there is a great workspace under the room. Air conditioner makes your life better in August. The food in cafe is also tasty.
From the other hand there were some really serious problems with the stay:
1) the internet router is far from the room - so the internet is really slow when you are in (sometimes phone can't even connect). The host said there is nothing he can do to fix it during my stay but will do it after (so the internet was awful for all 6 days).
2) The room is in the building where there is a cafe with really loud music every evening and night. I liked the music - great playlists :) But it is really really loud. I think it is quite impossible to sleep before 1-2 a.m. on Fridays and Saturdays. But music is on every evening though. Even if you close all the windows it would be still very loud because the music is from inside the building.
3) First and fourth floor are the cafe, second is a workspace, third - the WC and your apartment. So 5 times a day people try to open your door thinking it is a toilet. Didn't like that. Also in the evening people talk loud near your apartment while they are in the queue to the toilet.
4) Part of the lamps were not working but there were candles.
So I think its definitely not a place to spend your day and evening time in. If you are rent it only to sleep (and you come back home to sleep after 2 a.m. every day) and spend some hours during the day - its great if they will fix the internet. But otherwise you should know the cons I wrote about.