Yanna's place is very conveniently located near a bus stop that will take you right to syntagma square, and is also about a 15 minute walk to the nearest metro stop.
The place itself was lovely! It is perfect for long stays (I stayed for two weeks) with all amenities you could need, including a laundry machine. Detergent was even provided, as were any other cleaning products you might want to use (I cooked a lot while here so ended up cleaning up a lot.)
It's also a neat place for anyone who is really into David Lynch films, the theme for the bedroom being Blue Velvet.
The hosts were really quickly responsive, and the neighborhood was quiet, yet I never had to walk far to get to the nearest restaurant/coffee shop. I'd highly recommend this place to anyone wanting a stay in Athens.