This apartment is the best place we have stayed in Greece and Xenia was friendly and inviting, so this is really a terrific place to stay: The place was spotless, the A/C was very efficient, and there were some very nice touches to make us feel welcome. Her suggestions for eating were great (Fokionos Negri is an amazing place with all its cafes and tavernas).
While it's quite a walk into the centre of Athens, there are great public transport connections and a taxi only costs around €5, but it's worth doing that walk at least once. I really can't praise this place enough - I'll definitely stay here the next time I'm in Athens.