If you simply need a place to relax and rest during a trip to Athens, this is the place. The subway station is only about 1/4 of a block away, making it very easy to access both the airport and the ferry port. The location couldn't be better.
All of the check in instructions were spot on and once I had my bearings after exiting the subway the directions were really easy to follow.
I slept well while there. If you are a light sleeper, I might suggest wearing ear plugs in that the room is immediately adjacent to the main water closet, so you may hear the door opening and closing at night, but it really didn't bother me.
If I were to return to Athens, I would definitely stay here again. Well done.