If this apartment is available, book it! The unobstructed views of the acropolis and the Temple of Zeus are incredible. You are within walking distance of almost everything.
The building may not look great from the outside, but it is in a safe quiet area and the apartment itself is beautiful. My entire family loved it and my kids and I are hard to please.
Danai is a fantastic host. She was always very fast to respond and met us right on time. She also spent a good deal of time telling us about all the sights to see in the area. From the acropolis, to restaurants, to scenic hikes, Danai helped plan most of our time in Athens!