Eveything was fine with Dean and his team.
From the communication, to the meeting at the metro station, the explanations, to the chek-out...
The apartment is very nice, the neighborhood is awesome, you can get to the Monastiraki Metro station in 5 minutes walking, there's a great covered market just a few steps away, spice sellers, shops of every kind.
You're, really, 5 minutes walking from the real hart of the city. Psyrri is a lively area, you still can get real tavernas with real greek food and a lot of locals eating there while, if you prefer more easy stuff, you just walk down Athinas and you're in Monastiraki square, in front of the Acropolis.
The terrace on the roof is incredible, exactly as you can see in the pics of the house.
The only con is that on friday and saturday night the music coming from a club down the street was a little bit loud, so the room facing it can be a little noisy. Nothing unbearable. If you sleep well, no problem; otherwise, bring some earplugs and you will be ok (or book between sunday and friday...).
Absolutely recommended.