Costa was a really friendly and caring host. He gave some great tips for our Athens trip, answered quickly and was always there (via phone), if we needed something.
The flat itself is in walking distance to most of the important historical sights. The next bigger grocery store is a 10 minutes walk away. A small mini market is right around the corner. Some restaurants are also around the corner, so nobody have to starve.
The flat is good value for the price, spacious and clean, but for maximum 3 people or a family. The double bed in the bedroom was quite small for 2 persons, but comfortable.
Would recommend it, had a lovely time.