i would definitely recommend Vivian's place for staying in Athens.
First of all concerning the hospitality Vivian is such an excellent host she cares a lot about her guests, she did not stop asking us if we need anything or if everything is going good with us, even at one night my roommate forgot the keys in the car and the keys of the apartment as well so we had to woke her up in the middle of the night and she was not even complaining about it.
Great location, near to everything (Metro, Buses etc...) easy access to the touristic areas and attractions.
The place is very big and spacious and very clean also.
Don't think twice about it guys Vivian is the best for your stay :)