Gertsanik is a great host - she replies very, very quickly, willing to help and gave us some good recommendations. It is very nice and easy to communicate with her.
The place is perfect for travellers who want to explore Athens - it is seconds away from a metro station which connects with the main tourist areas, even though they are in a walking distance, as well. The National Museum is 10 minutes by walking and Monastiraki square - about 20-30 minutes. The neighbourhood is not "tourist attraction" but is very comfortable having several coffee shops, supermarkets and other stores.
The apartment is small but just perfect for 2 persons. It is extremely cosy, well organised, clean and with all amenities you may need. The only thing to have in mind, which I don't consider as an issue at all, is that the toilet seat is right next to the washing machine and it is uncomfortable for a bigger person.
Everything was perfect and I definitely recommend the place.