To be fair the host is extremely flexible, responsive and helpful. However, the apartment we got was very unlike the pictures. Some things were broken, others stained or cracked. The Host was responsive and easily moved us to an apartment that was way more comfortable with a better upkeep (yay!) but it had an unbearable cigarette smell 🙃. A smell that resisted hours of open windows, a smell that our noses couldn't even stop smelling even after many hours of sitting in it hoping that our noses would grow accustomed, a cigarette smell that stayed in our clothes until after we left from simply being in there. At that point we decided to cancel and be reimbursed by appealing to Airbnb.
To be fair once again, the host told us that he would have had no problem obliging and moving us to another, completely different property of his.
The checking process is simple as it is associated to a hotel with a round the clock front desk which is nice. Also calm neighborhood, close to Hagia Sofia.