We stayed at Efis apartment for a whole week for new years - and we enjoyed it a lot! It is absolutely central, you can even see the house from inside the acropolis museum! Walking pretty much everywhere is totally easy and the flat gives you everything you need. It took me some time to make friends with the shower - but the trick is too heat it up muuuuch longer than 10 minutes ;) The kitchen has pans, pots, cutlery, a microwave, toaster, water boiler... all you need. The bed is wonderfully spacious, the flat perfect for two. Efis was always ready to help us with any kind of problems and questions that would come up. I can definitely recommend her place for a lovely time in Athens!