Had a good stay of five nights at Yusuf's place, communication was great throughout with very quick responses to messages. Yusuf was able to set up airport transfers for us to and from IST which we paid for in the lobby, which was much appreciated.
As for the unit, we liked the comfy bed and the daily cleaning service, but had to take a star off for how loud the building was making it difficult to sleep. It seems we're either through the wall or right below a large family. There were loud voices and children running up/down stairs until 11:30pm or midnight some nights, making it difficult for us to sleep.
We only went up to the roof one night to check out the sunset, but the view was very nice and I could see having a picnic dinner up there or bringing up a bottle of wine would be fun.
The shower had very low water pressure and the towels provided were thin and were unraveling at the edges, making it difficult to really feel clean for us.
The wifi was disappointing, speedtest.net never got above 2-5Mb/s down and less than 1Mb/s up.
We didn't book the sauna/bath or go see it, so can't really review that. Seems nice to have as an option though.
All in all, Yusuf's palce is a good value compared to hotel prices in the area, so I can't say I was unhappy with the stay at all. There were some definite downsides, but depending on what you look for in an Airbnb, not dealbreakers at all.