We stayed at Yusuf's place for three nights. We had a really good time there! Yusuf is a really, really nice host, and he and his staff are very kind and very warm people! They are really keen to help with any questions, to give tips where to go in Istanbul, how to get somewhere, where to eat, etc. We could get a good cup of coffee at any moment. The room itself was also good, it was stylish and had all we needed for a good stay. The rooms were being cleaned every day. This place is also perfectly located. It is located near all main highlights of the city (Blue Mosque, Hagia Sophia, Grand Bazaar, etc.), you can easily walk to all these places. On top of that there is a tram stop within 5-10 minutes walking, which also leads to all main points of the city. I would highly recommend staying here and will definitely go back here if I'm visiting Istanbul again.