Yusuf is an excellent host. I booked last minute due to an unexpected change in my travel plan. Yusuf was very responsive and even waited for me in the street because the taxi driver did not speak any English.
It was a very short visit to Istanbul but was very pleasant in terms of comfort and location. The space is located in the old(ish) part of town. You get first hand look at regular Turkish people's daily live. I loved that. The neighborhood is not fancy but I liked it a lot: it is very safe and close to must-see spots (e.g. SultanAhmet).
Finally, while it is true that many sellers in the stores try to charge higher prices to tourists, most are very charming and skillful so paying a bit more is not a great displeasure. I guess that is what you need to pay to witness an amazing tradition of trading and commerce that dates back three millennia or more. :)
I just hope Erdogan is not in power forever... but I guess saying more about it would be off-topic.
Enjoy Istanbul!