We stayed at Maria's house in Plaka for 3 nights. As they say "location", location, location. The Aptment is literally 10 steps from the Athens steps and super close in proximity to many of the main attractions like the Acropolis, Monistiraki square and market, Syntagma square, Temple of Hephaestus. There are at least 5-7 vegan restaurants within 10 min walking distance which was extraordinary. The terrace view at night of the Parthenon is amazing.
The only caveats were
1. The Aptment is located in a very narrow street which is inaccessible by most vehicles during normal hours and you will need to drag your bags a block or so which can be difficult for older travelers with large bags. Wasn't a big deal for us but could be an issue for some.
2. We were visiting in Nov and the water heater is a little funky. You need to turn it on well in advance 45 mins or so before you can take a shower and the hot water lasted for about 2 showers before it ran cold again. So plan accordingly.