Ich can only recommend this place for your stay in Istanbul. You can easily reach all the touristic places by public transportation. The ferry is only 10-15mins away if you walk there by foot.
Deniz is a really good host and you can contact her almost 24/7.
Check in and check out both were also uncomplicated.
The only negative point was the smell of cigarettes in the entry area of the building.
I would definitely come back