If you're staying in Naples for any length of time, you MUST stay with Valentina and Dario. Not only are they the most kind and amazing people you'll meet on your trip, but their B&B is top-notch. It is on the top floor of an apartment building (with elevator access) and includes a gorgeous terrace with a view of Mt Vesuvius when eating breakfast. The breakfast served is fantastic and a great start to the day.
The room itself is enormous, clean, with a very comfortable bed and effective AC. The "private" bathroom is right across the hall, although its location did unfortunately lend itself to other guests using it occasionally. No big deal.
The location of the apartment is very central. 10 minute walk from the train station, along a main busy road full of stores and restaurants. Despite this, the room was very quiet in the evening with the windows closed. It's also a 15-20 minute walk to the port where you can catch a ferry to Capri or elsewhere. No matter what people tell you about Naples, we felt very safe where we were staying and everywhere we walked, even at night.
Valentina would call taxis for us when necessary and even provided us with some beach towels for when we went snorkeling. They are truly the most down to earth, lovely people you will ever meet. We miss them dearly and we hope to visit them again. They take their job very seriously and are extraordinary at it.