For a beautiful place, a wonderful host, and a cool neighborhood, you can't beat this. Stayed for two nights in late May. The apartment is huge and beautiful, with lovely views, especially from the rooftop, which we frankly should have spent more time lounging on. There's strong air conditioning in the bedroom (very helpful during the warm front we encountered) and a good washer/dryer (super convenient). NOTE: This place is on a hill, and it's a two-floor walkup, so this sadly isn't for you if you have mobility issues. But the payoff is great views over the rooftops and the church next door.
The best part of this place, though, is the host and the location. Stavroula was in touch way before our arrival to make sure she knew when we were coming and so she could be sure to be at the apartment to meet us. Upon our arrival, she gave us a helpful map and tips of places to eat and see around the neighborhood, and texted further tips, based on on interests, even after she'd left us. Speaking of the neighborhood, it was our favorite in Athens. Easy walking distance to a charming square ringed with tavernas, and a street called Troon that's home to many wonderful restaurants and a little repertory outdoor cinema. The vibe is laid back, arty but totally unpretentious. This definitely feels like a modern gentrifying area — it may not be for you if you want old-world Greek charm without any grit — but it didn't feel at all unsafe. And yes, you can walk to the Acropolis from here. Should we return to Athens, this is where we're staying.