I'm torn on this review. Maybe I'll just do pro/con.
Pro: Tremendous location, walk outside and you can see the Parthenon (it's farther away than it looks though!). It's not even 5 minutes from the Thissio station, somewhere between 5-10 mins walking from Monastiraki station. Wifi was really solid. Apartment was nice and clean. Modern. Fairly quiet.
Cons: Finding the place the first time is hard. It's a predominantly pedestrian area, so that is nice, but it doesn't help when arriving. The cab drivers don't seem to know where the place is, my cabbie must've asked 5 other people and only when we were right there already did we get anyone who seemed to know. Google maps isn't a help either, it'll lead you in the right general direction it SEEMS, but the numbers on the street don't follow what they indicate. Oh, did I forget to mention there's another building with the same address across the street? Evan doesn't use whatsapp to keep things straight I guess, I can understand wanting all his bookings and whatever in the whatsapp inbox, especially if there's multiple listings, but I really could've used some real-time directions. A picture of the outside with the ID 24/7/365 sign would do wonders! You can't miss that sign its huge. The apartment is also directly above a bar, it's not a big bar, lots of beer choices, feel free to go in, but Fri/Sat they're open pretty late, so if you're a REALLY light sleeper, something to consider. Lastly, the hot water. Works perfectly, only if Evan gives you the instructions on how to use it.
My cons section is long, but it's really only 2 little things, if Evan really doesn't wanna do whatsapp, that's fine, but one really good email with a picture of the outside of the building and the hot water instructions would've solved all of this. If you're arriving during the hours the metro is open, it's fantastic, if it's late, you can still get the bus to Syntagma, it's an easy walk IF you know where the place is already. Another good point about the location is at least 2 of the "hop on/off busses" stop basically right in front of the apartment, the yellow and the blue ones, fwiw. I dunno about the red.
I would 100% stay here if in Athens again. Also the aircon is solid if you're there in summer and need it.