Now, as I do have another accommodation to compare with, I want to comment the ‘Youth Station Hostel’ in Rome where I stayed for the first two nights. So, the hostel’s location is near the Piazza Bologna, which is a stop of the underground ‘B’ versus ‘Ribibbia’.
I arrived in the late afternoon without having a reservation. The hostel is rather well-known and therefore always booked out. I was lucky to get a bed in a room for 12. 
Another thing you have to try out once. The room had a bathroom and toilet for the 12 of us. Everyone had bed, sheets, lamp and locker at his disposal. So you got everything you need.
I would not recommend such kind of accommodation to people with light sleep, as everyone comes home whenever he wants (the reception is open 24/7), so it could happen you wake up 11 times a night.
The receptionists are very friendly and helpful. I asked how to arrive at the airport the night before my flight. It obviously was not their fault, I missed my flight! 
