Clean lovely airport. The authorities should ensure that selling water airside is a reasonable price. They take fluids off you to pass security then allow charges of €6 for a bottle of water worth €1

My checked suitcase was crashed at the airport. I claimed the damage, received all the necessary documentation and was promised replacement in a week. However, when I was leaving Greece the airport service took advantage of the situation and refused to reimburse or replace my damaged luggage. They lied that I haven't submitted the damaged suitcase dimensions. When I began to insist they simply ignored my messages. This was shameful behavior.

The pros of Athens Airport is that it has good and reasonably priced food and beverage options (the food at the self service before passport control on the departure level is decent and you can buy water and toast for subsidised prices even after the security and passport control near the departure gates, i.e a bottle of water for only half a euro!).
There is a baggage storage facility on the arrivals level which is especially useful for those flying to the islands or other destinations for a few days and don't want to carry their suitcases with them.
The cons are that the airport is relatively far. It takes 60 to 90 minutes to reach most destinations on the metro line from the airport. The ticket is for 90 minutes and the train frequencies are less than in the past (perhaps due to covid-19) so it often happens that a traveler buys a 90 minute drive ticket but finds the ticket has expired once he/she reaches his/her destination despite it not being his/her fault the train was delayed at arriving and he/she waited at the platform an extra ten to twenty minutes...
Another disadvantage is that the only accommodation option within walking distance of the airport is the Sofitel Hotel which charges daily rates starting from 180 EUR and has no hourly facilities (or four to six hour slots to freshen up and power sleep) which is an option many other airport hotels in Europe provide.
On the bright side the staff at the airport are all professional with excellent English speaking skills.