Pangrati Studio II is a great studio apartment centrally located in Athens. It's easily accessible from the airport by subway (about an 8 minute walk) from the blue line.
Yiannis, the very personable rental agent, met me at the apartment with the keys and gave me a tour, emphasizing that I could call him if there was an issue or problem.
The apartment was as advertised and pictured, an L-shaped room with separate kitchen and bathroom. The kitchen was decently equipped with the basics and also had a washing machine. The bed was a comfortable double in a separate sleeping area. Sheets and towels were provided.
A large balcony wrapped around the whole apartment and had chairs and tables for lounging and dining. If one has friends in Athens, the balcony (with a view of Lycabettos Hill) could be used for entertaining in good weather.
Both the building and neighborhood are safe, and there seemed to be a permanent patrol car parked several blocks away...