My fiancee and I stayed in Theodore's apartment for 4 nights, and really loved it.
Theodore is an excellent host, and was there to greet us when we arrived, and showed us the apartment, as well as going through his tips and recommendations. He has also built up a nice booklet of information which was great, and we used a lot. We took several of his tips for places to eat and things to do, and they were all excellent.
The apartment itself, while small, is extremely well equipped, and never felt cramped. It had everything we needed, and the balcony is a wonderful resource - it catches the sun from about 11am until sunset, and is quite private. It has a perfect view of Mt Filopappos and part of the Acropolis. The kitchen is also well equipped, though we didn't end up cooking. The bed is very comfortable, and the shower was excellent.
Public transport is very close-by (approx 2 min walk) for both the metro and the tram (which we used extensively), but even walking to the Acropolis only took about 20 mins. A supermarket is also only about 2 mins away, which was also very useful.
All in all, this apartment was just about perfect - we would definitely hope to stay here with Theodore again.