Ona is not a bad place, but it is truly a hostel so do not expect any of the amenities provided by a hotel. The double room was bare-bones, with one bedside table, and no closet. The private bathroom had a sink so small that you banged your head on the wall if you tried to wash your face. The "window" in the room opened into a vertical ventilation staft; in NorthAmerica this room would not meet fire codes because of the lack of secondary egress.
The entrance is hard to find, even more difficult at night as the signage is small, and the outside intercom to reception is poorly labeled.
The staff are young and friendly.
The kitchen area is fine, but the common refridgerator is packed with food. The sign on the outside of the refridgerator says it will be cleaned tomorrow. Tomorrow never came while we were there.
If you don't want amenities and just a place to sleep Ona is great.