We stayed here for 3 nights and was a great location to explore the city.
We got the metro from the airport to monasteraki station and from there was an easy 10 minute walk!
Room was true to pictures, large but basic. Air con was good and WIFI was fast.
Found the lift a little bit intimidating at first but soon got used to it (not the biggest fan of lifts in general!). I would also make sure you have flip flops for the shower as they are communal.
The place seemed secure with a lockable front entrance, key code to corridor and key for room. The street outside is also well lit.
Plenty of bars and restaurants nearby! We enjoyed the restaurant opposite as a cheap option.