The unit itself was clean. It is close to the metro and about a 25 minute walk to The Acropolis. There are restaurants nearby. The neighbourhood is unattractive and I wouldn't feel comfortable staying there as a solo traveler.
Demetris was unresponsive, although his listing says he is available 24/7. In the evening, around 19.00, I asked him to help call us a taxi for the morning-- we do not speak Greek and the address he had provided was written in Greek. He never responded.
I left a shoe at the unit and realized only after we had checked out. However, I was going to be in Athens a couple of days later, so I messaged him and I asked if I could swing by and grab my shoe. He responded quite quickly, which was nice, and said that yes, I could come by on a day that suits me between 12.00-14.00. I responded again, clarifying, 'are you sure my shoe is there?' to which he assured me it was. So, I planned my day around being there between 12.00-12.30. I took transport (30 minute commute) and messaged him when I arrived at 12.10. He responded, 'We will be there soon.' 16 minutes later, he had yet to arrive, so I messaged again. It was at this point that he informed the cleaner was at the unit and that the shoe had been thrown away the morning we checked out. He generously offered to reimburse me for my taxi to the unit; we paid €37., but suggested he reimburse €25. (we were probably charged a 'tourist tax' by the driver) to which he refused and said €20.
If, at the beginning, had he said the shoe was gone, then okay, I made a mistake. I would probably provide direct, private feedback and suggest that he do something similar to hotels-- message the person who left the item and offer to post it back for a fee... However, he never actually went to the unit or asked the cleaner about what had happened, which caused me a major inconvenience.
Demetris' disconnect from the unit was quite unfortunate. I, personally, like the community feel of AirBnB, and when someone runs so many units, the community feel gets lost and the disconnect can take away from the experience.