The apartment itself is one of the cleanest looking ones that I have seen in my search. The communication before and after booking was excellent. But their inability to be flexible in their refund policy, especially in these uncertain times and ever changing circumstances, combined with the location of the property makes the value 3 stars in my opinion.
I needed to book a place urgently because of family health issues, and booked without having a chance to do a more in-depth research beforehand. I booked for two weeks on a Sunday to arrive on the same Tuesday. The day I arrived at the property, the circumstances had changed and I was able to stay at my family's home. Wanted to cancel, but I offered to pay for the first week regardless, for the inconvenience I caused, but they refused to refund the second week due to their strict no-refund policy.
I do understand their policy, and it was stated on the profile. So I am partly to be blamed, and I own my part. I wish they were able to be more flexible though. Chose to write it here not to do harm to the property but to potentially help someone who reads the comments before booking to help them out.
Growing up in Istanbul, I would not recommend that neighborhood. Because the exact address is located AFTER you book, you don't get a chance to see where exactly the place is located. But the general neighborhood Kustepe, is not one of Istanbul's best.
I own my end of the blame. I should have not booked before confirming the location, and shouldn't have booked for two weeks in such a volatile time. I wish the host was able to adjust the refund to a week, which I think is would be fair.

Everything else was PERFECT about this host, but the location and the strict cancellation policy.