If you're thinking about staying anywhere else--stop, and stay at Fotini's! Perfect neighborhood, perfect apartment, perfect host.
Petrálona is the best because it's so centrally located, yet completely off the beaten tourist path. We didn't see a single other tourist the 5 days we were there, so you really feel like you're in a real Athenian neighborhood. Also, it's about a 3 minute walk to the Metro, and it's very easy (one transfer) to get to & from the airport. The trip is about 1 hour 20 minutes. A few tips: be aware of how often the line to the airport runs. Sometimes it's only about every half hour, so don't cut it too close. When you get to the end of the line of the second train, you just get off and wait for the line that runs to the airport. Also, make sure when you're buying your tickets that you buy the airport one. We had tickets we had already bought, and since whenever you use the Athens Metro you need to keep your ticket until the end to exit, we couldn't exit, and 2 "officials" came over and tried to fine us! This would've been really stressful if we hadn't given ourselves a lot of time. Also, if you're taking a ferry from Pireas port, you can get there on one Metro line in about 19 minutes! (Make sure when you enter it into Google Maps you spell it "Pireas" or you'll get different directions.)
The restaurants in Petrálona--don't even get me started. Amazing (and affordable!). We went to a lot of the ones you'll find on "best of Petrálona" lists, but honestly I don't think you can have a bad meal in this neighborhood. Follow Fotini's neighborhood/city tips, they are wonderful!
The apartment itself is amazing, stocked with anything you might need, a huge balcony in the front, and a smaller one off the bedroom in the back, and it feels spacious and calm. There's a huge supermarket next door, and the building and Petrálona are very quiet late at night. The apartment air conditioners are wonderfully quiet and efficient, and cool off a room almost immediately even on a low setting. The shower is hotel quality. There's a small washing machine, but honestly the humidity is so low in Athens that you could probably pack 1/3 of the clothes you're planning on, and just quickly hand wash each night. There's a clothesline out back, and things dry in a couple hours.
Finally, Fontini is one of the best Airbnb hosts we've ever had. From the beginning when I immediately wanted to change my plans after booking, she was accessible and flexible. She makes herself available at any time on WhatsApp, and even called to make sure we had checked in alright. I'm only sad that we didn't get to meet her, but since we will 100% be returning to Athens and this apartment, hopefully we will! Thank you so much Fotini! ♥️