We had an absolutely wonderful week-long experience with my wife!
Yusuf is truly a great host! He is very friendly, easily approachable and always willing to help with any possible issues or needs of his guests. The room we stayed in was rather small yet included all the necessary things for a ~10 day stay. To our surprise, we found an extremely helpful guide in the room written by Yusuf himself. It was perfect for food-lovers and museum visitors like us :) The guide lists many nice food spots both to grab a snack or to have a full decent meal. Many of the mentions are followed by Yusuf's personal comments and small jokes.
The place itself is situated very close to all the cultural center of Istanbul, so all the main sights like Haghia Sophia, the Blue Mosque, Topkapi Palace Museum, Basilica Cistern and many other museums, parks and smaller mosques can be reached within 10-15 minutes by foot. The markets, such as the Grand Bazaar and the smaller one Arasta Bazaar, are also rather close.
So, it is great place to stay in Istanbul for those who want to easily visit the main sights and to try some gems of the local cuisine and street food! Absolutely yes!