I loved the studio, excellent location, you can go to all the points of interest walking, and the main station Monastiraki is quite close.
The transfer from the airport can be by subway if you're traveling with one suitcase.
It is very close to Psyrri and Plaka, each with their own special places to eat and have fun. So it's very easy to eat around the wonderful greek food, or eat in the studio, well equiped.
I felt safe walking the streets around the studio late night.
It took me 5' to figure out the check in, and the ladys in the small shop at the side of the building entrance were quite nice helping me.