This apartment is very comfortable starting with the open and spacious living room, dining room and kitchen. The bedrooms each have an enormous amount of closet space and the beds are comfortable. The kitchen is well stocked with utensils and the appliances all function properly. The decorations are very nice, including a lot of custom mosaics created by the owner, herself.
Syntagma Square is about a 30 minute walk and the number 6 tram (1.10 Euros) can take you there in about ten minutes. It is about a five minute walk to the number 6 tram. From Syntagma Square the X95 Express Bus (5.50 Euros) will take you to the airport in about 45 minutes. It runs all night, generally with only a 15 minute gap. Of course, coming from the airport this trip can be reversed. The cost of a taxi from Syntagma Square to the apartment should cost no more than 5 Euros if you have a lot of luggage.
The balcony from the bedroom has a view of the Parthenon. Walking to the Parthenon takes less than 20 minutes. The Acropolis Museum is even closer.
The balcony on the other side of the apartment (street side) runs the entire length of the building. There is minimal traffic on the street and since the apartment is on the 6th floor (USA counting), road noise is between minimal and non-existent.
For exercise, you can take one of the many trails over Filopappou Hill. This giant park contains many impressive views of the Parthenon. There are also a host of trails through the National Garden which abuts the Parliament Building and Syntagma Square.
Covid tests (both PCR and Antigen rapid) are available at Homed (near Syntagma Square) for very reasonable rates (PCR 47 Euros). Antigen results are available in an hour or less and the PCR test is available the same day provided that you take the test before noon. For a significant surcharge, a PCR in the afternoon can also get same day results. Obviously, if at all possible, get your test in the morning.
There are a number of small and medium sized grocery stores within easy walking distance. There is even a full sized Lidl about 20 minutes to the south.
While I haven't taken it since my earlier time in Athens, there is good public transportation to Piraeus where the ferries leave for the closer islands.
All in all, this is an excellent apartment to stay in, whether for short stays or multi-month stays like mine.