If you are looking for a place near the main train station to get in and out early in the morning or late at night, Hostel Pensione Mancini may be a good option. The train station can be easily reached on foot.
The hostel is located in the middle of a busy and crowded market in Piazza Garibaldi. Look for the big sign of the hostel on the street before reaching the supermarket at the end of the street. The sign can be easily missed since the street is overcrowded with market vendors and people. The surrounding neighborhood is absolutely noisy, filthy, and hectic. Perhaps it might give you a sense of truly being in the core of Naples. However, for the price of dorm room, the hostel does not offer the fullest comparable services.
It is a small hostel run by a family. They have three rooms for the dorm rooms. Each room has different number of beds (no bunk beds). The hostel description indicates that dorm rooms come with free lockers, however, the two dorm rooms on one wing do not have any lockers. There is only one bathroom and toilet for everyone. But because of the hostel's small size, it's manageable. It's not immaculately clean -- some soap scum on the tiles -- but fairly good for old European buildings.
There is no separate common space, but the kitchen serves the both purposes. It's sufficiently roomy and cozy. It is fully equipped to cook and hang out with people to chat. Free breakfast is provided from 8 a.m. to 10 a.m. According to their brochure, free cappuccino, espresso coffee, and hot chocolate are available for breakfast, but they were not available when we asked for it in the morning. They do provide instant coffee for breakfast though.
There is one computer for free internet for guests. However, no wireless internet is available at the hostel. As it is a family business, you see the same folks at the reception and around the hostel. The staff come across as unfriendly, perhaps as a result of the cultural difference or maybe something else. Although some of the staff do not speak English very well, they seem to be concerned about the safety of their guests. Upon request, they provide helpful advice and tips about Naples.
Overall, the rooms are decently clean, and the hostel offers basic services of typical hostels. Its close location to the main train station can be ideal for some travelers. If you don't mind being in the center of busy, seedy, noisy, and filthy area of the city, this hostel may offer a decent place for a short stopover to meet other people and explore the city center.