We had a great time at artharmony.
We loved the design of the room and the whole hostel. The place is 10 minutes from the turist center, 5 minutes to the metro stop. Great location! Great communication, there are 2 computers and you can also print pages (on extra payment).
Please note that there is no elevator, the room are either on the 2nd or 3rd floor. The reception is on the 3rd floor.