I didn't meet Dimitri in person but Mamah, the Greek neighbour who welcomed us was friendly and helpful despite not speaking a word of English. We had a misunderstanding about the beds (we needed 2 beds) but I messaged Dimitri and Mamah popped back up to sort everything out. Communications with Dimitri was excellent and he always responded within minutes. He was flexible with the check-out time which made our lives much easier.
The location was ideal - it's just out of the touristic part, and somehow felt more authentic. You can get to the Acropolis, or to anywhere central, in less than 15 minutes on the metro (which is super cheap, 9€ for a 5-day pass). The flat is a 3 minute walk to the metro station.
There is a lovely cafe (Streatcafe) as well as an amazing cake shop (Pronto) and a supermarket between the flat and the metro station (Attiki). All very convenient.
However, the flat looked a bit more 'run down' than on the photos and the bathroom, though fine for me, was very impractical for my friend who is tall.
A couple of saucepans would be good for people who wish to cook/ warm up something in the kitchen, though we just decided to eat out.
Overall, an enjoyable stay, and the view is really lovely as mentioned in other reviews.