Absolutely stay here!! The apartment is much more spacious than we expected. (We were even able to spread out yoga mats and do yoga in the living room in the mornings!) The decor is lovely and unique. The view from the balcony is incredible. And the apartment in the most perfect location!!! Virtually everything you could possibly want to see in central Athens is within a ten to fifteen minute walk. Shopping (and ice cream!) is right outside the front door. The area is very safe and lively, but quiet enough at night that your sleep will not be disturbed.
There was a bit of a learning curve on operating some of the kitchen appliances and the hot water heater for showers, but Marina was very responsive to all our questions.
If you're going to Athens, stay in Marina's apartment if you can!! (And if you can't, at least try to get a place in Plaka!)