We (2 grownups and a 4 year old) stayed at Galini's flat for three nights and we felt very good there.
The communication was flowing perfectly as Galini always answered very fast. Also the check-in and check-out were really easy to handle since handled via a system of lockboxes, which helps if you need to check in/out very early/late.
If you are into young (still mixed with older) popular neighborhoods, Exárcheia is the best, with its load of cafes and restaurants, bookstores and various hip places, but it might not be for everyone. and if you are in for the "old" you can even easily walk to the Acropolis and its are (we did it with our four years old).
The only little minuses was the really limited amount of crockery/cutlery if you really want to cook on the one hand (again the neighborhood offers so many great and various breakfast, brunch, lunch, dinner possibilities) and if you have any kind of back issues/sensibilities, I'm not sure I would recommend the bed in the living room.
All in all we were really happy with our stay there and would recommend especially to younger groups and families who want to enjoy a nice time in Athens, a little bit further away from the super touristy places.