I went alone to france and ended up always having at least 2 people to tour with. The showers can be idiosyncratic and it is frequented by school groups. They have free lock boxes for valuables. I stayed for 8 days and heard no reports of theft. The rooms are cleaned thouroughly every day.
Beds have a pillow, bottom sheet and comforter.
If you find yourself feeling ill they have a kit with cold,headache,stomache meds etc. which they will give you at the front desk. The receptionists Eve and Carlotte were especially helpful. They show movies at night for free and have got pretty good food. By metro, get off at Bonne Nouvelle station. 100F per night per person, includes breakfast.