I stayed in Villa Galley with my friend. Here is my review, and below you will find hers.

The listing was accurate. It is a small boutique hotel - I believe they have 9 rooms in total.
Location: In my humble opinion, cannot be better. You are close to Bosporus, Little Aya Sofia is just around the corner, and it would normally take me about 5 minutes to walk to the Sultanahment Square. On the other hand, the neighbourhood is quiet, and serene. It is a beautiful area to come home to after a long day of exploring.
Hospitality: Superb! Can and Mert, the owners, are truly wonderful. They are supportive, sweet, caring, modern and cheerful. They will make you feel completely safe.
The room: Very clean and cared for! Powerful aircon, a comfortable bed, and nice modern shower (with proper water pressure!).
The kitchen: Small and neat. I spent many an hour reading there in the evenings. You can make tea, cook, and use the refrigerator.
-Dara

"Galley" is an awesome place to stay in Istanbul if you are looking for a quiet and comfortable one. I felt like at home and every evening after full of impressions day my friend Dara and I with pleasure were spending time at cup of Turkish tea with our new friends at kitchen. That place seems for me a real home far away from home.
-Kate