We stayed in Piraeus rather than Athens to have more of a seaside vs. city experience over the 9 days we were in the area and were not disappointed. Dimitrios was a wonderful host, even driving to the Athens airport to pick us up at 1:00 a.m. when our off-season (February) plane arrived and the taxi driver he had personally arranged for us could not make it.
It's a beautiful and modern studio apartment, very quiet, safe and secure building with close-by full grocery store (be sure to look upstairs also), and good restaurants within (short) walking distance. The one-way main road with bus service was very frequent going to the Port of Piraeus, and a quick walk from there to ferries or metro (one single or multi-ticket) card purchased from machines at Port and various metro stations can be used for bus/metro and possibly train (though we didn't use the suburban train). It was easy to get around and into Athens in about 30-45 minutes via bus then metro (or even suburban train another block farther). Also can walk (uphill) to more bus lines to get to other locations around Piraeus.
I have posted a fuller review on AirBnB which we used to reserve this wonderful property (same description used as here in TripAdvisor/Viator). Be advised, that from the first floor apartment we stayed in you do not have the water-view, but can very easily walk to the view that is shown. The studio apartment was comfortable, extremely clean and our host even provided us some essential foods for our first morning after arrival. Our kind an gracious host who speaks very good English, owns and was on the property and very responsive through the messaging system.
Another note: Because we stayed a long time in one place, we purposefully planned to do laundry half-way through the trip and found a self-service laundromat (more often available are laundry services within dry cleaners, which Dimitrios offered to recommend). Very clean laundromat (with newer english-languange machines) on google maps near Monastiraki Square metro stop (associated with the "left-luggage" service nearby). Very nice and friendly owner provided change for our bills for the 3 washers/3 dryers machines (or save your own coins up ahead of time). Cost during our visit was 5 euros for wash, 1 euro for 30 min of drying time, older reviews on Google mentioned the same pricing as this.
Great location right next to the coast, supermarket and great restaurants; quiet location, free parking. Dimitrios was very helpful and welcoming. Will go again.