I used metro to go to Athens from the airport which was very comfortable and fast for 6 euros only. To go to the airport from the city I used a metro train to Plaentias station and then changed to Proastiakos subburban train which was almost empty air conditioned fast clean and comfortable. Airport check in was quite fast in a big bright hall. Many signs showing directions to gates passport control toilets and all other necessary information. There are a lot of shops with souvenirs music CDs different beverages sweets olive oil and all the other food. Most of such shops have reasonable prices but some I found to be a bit expensive compared to the city. The airport is not overcrowded which helps a lot even in top of tourist season. Staff is pleasant and ready to help and explain anything you may ask. Luggage is easy to find and everything goes very quickly. You need just some minutes before you leave the airport when arriving Athens. The only obvious problem about this airport is the passport control - both in arrivals and departures. when arrived a huge crowd of people from different planes went into one small hall with few officers working there. If you have Greek passport - it is OK but for non EU citizen it was about 15 minutes of waiting. Same when departing though in departures there is much more space but again in many cabins only few officers were working. Good thing is they don't take much time checking anything and the crowd goes quite quickly.