Guys, if you are going to Athens and have this choice available, you are lucky!
Vakis is an awesome host, very polite, helpful and just an awesome human being:) He provides all the essential info about the city and really quick to answer all of your questions. Vakis also gave us a very good perspective how to continue our trip and where to go.
The apartments is situated right in the heart of Athens, in 10–15 mins by foot from the most of the major landmarks, so you can check it out during your first walk. 15mins/10€ by taxi to the closest beach.
The flat is tidy and large with 2 balconies, we had a couple of nice dinners there. When we arrived a bottle of wine was waiting for us and fringe was full of snacks, so we weren't worried about firs breakfast.
Overall this choice made our trip. Thank you, Vakis!