The location is great — it is a good district for the first visit to İstanbul, cause it is close to the city center and there are a lot of cafes, but it is not crowded by tourists and quite calm and silent. Also you can have a view on Bosporus not living the guest room (or from the opened rooftop).
There are a lot of plants and the biggest cat I’ve ever seen, but it is very friendly.
Eylül is very hospitable and I can recommend you to have a breakfast at the cafe she is working at.
Talking about minuses of the flat I cannot mention the bathroom — it is not in the best condition and there is no door to it, so the flat is mostly suitable for one person or a couple, though it is clean, just need some repair works.
As for me, I would love to stay at Eylül’s place again.