We loved our stay! The host met us at the metro station and gave us a brief introduction to the city. We were dehydrated from all of our travel and he even had cold water waiting in the fridge. The location was great; walkable to pretty much everything. Acropolis took us maybe 15 minutes to walk to. There's a cool rooftop bar nearby called Cafe Zen that offered cheap drinks (at least compared to US standards) and great food (veggie friendly). This flat is out of the main touristy drag (it feels a bit more like a combination of visitors and tourists), which was nice.
The only thing I'd suggest is maybe bringing earplugs and an eye mask. For all the awesome things this place has to offer, it's very loud at night (I don't think the Greeks ever sleep!!) and the room never becomes particularly dark (though the host is upfront about that in his listing). If you are a light sleeper, you may want to be prepared.