The apartment has met my expectations. It's not big (as it is an attic apartment, the ceiling is slightly lower than standard) but clean and fully functional (I cooked my own meals). The best thing, however, is the location. Within a 20min walk there are so many sights to see it'll take you 2 or 3 days to visit them! Also, the Santagma square with transfers to the airport is 15mins away on foot.
The only time I needed any kind of transport other than my own feet was the trip to Delphi. So, very convenient indeed. On top of all that, the apartment has a wonderful view of the city.
As for the host, Thomas is a very friendly person with useful tips for tourists. He always responded immeditely to all my messages and was as helpful as possible.
Overall, fantasic experience :)