Eleni's studio is nice and cozy. It has everything you need: a big bed, one big table, a small fridge and a coffee pot... and she even gives you some clean nice towels, as well as shampoo and this kind of utilities. One of the best things of the studio is the super big terrace with views to the Acrópolis (well, you have to stand up to see it, but it's very nice anyway).
But for me, the best thing is the location: in a small and super quite street, it's only 20 minutes away from the Acropolis (walking distance), and basically anywhere you want to go is super close. We never had to take the subway or the bus.
We didn't have the chance to meet Eeni, but her father was very helpful and polite and he even called a taxi for us when we had to leave to the port.
If I have to point out something not so good, I would say that the bathroom is really small, and that the recommendations left by her in the table (she left some documents with recommendations of restaurants and bars) were in greek so it was not very helpful (we couldn't understand anything).
But our stay was in general very very good. Totally worth it, we will come back! :)