We really loved our stay in Lenka & Tamara's place. It was very clean, very well equiped and very nicely furnished. The good surprise was the size of the rooms : really big and spacious with and XL bed in the main bedroom. Though the flat has no air conditionning, it was cool enough thanks to the numerous fans.
The location is also perfect : very close to everything (pedestrian shopping street, Plaka, Acropolis) so it's possible to come down for an hour or two, come back to the flat to rest and get away from the heat and got out again later when it's cooler.
Last good point : the very good and very cheap place to eat downstairs, at the corner of the street.