Excellent hotel to stay despite the sketchy neighborhood. Although it's close to monastiraki square and other popular areas, walking towards your hotel at night could feel a bit uncomfortable. Nothing happened of course, but always use caution. However, once inside the hotel, you feel perfectly safe. The room was very super clean, staff was always available in case you needed anything.
On a side note, I'd recommend taking Omonia station to get there, a bit of a longer walk to get there but better access for your luggage.
Overall an affordable, secure and clean hotel to stay in Athens.