Short summary: Roberta's place is a great place to stay in Naples.
Roberta is a very generous and helpful host.
She offered my wife and me a bigger room with a larger bed free of charge before we booked and did everything in her power to make us feel at home in Naples.
She welcomed us with a drink of cool lemonade and coffee, which was really refreshing after travelling by public transport from the airport. She gave us tips on places to visit and where to buy quality local food. Whenever we had a question, she answered in almost no time and did her best to find a solution.
The apartment was clean and quiet. The balcony offers a great view of Naples and Mount Vesuvius, we spent all our evenings there to simply enjoy the atmosphere.
If you decide to visit Roberta (which you should), I would recommend to explore Naples using public transport. Roberta's place is easily reachable by subway (10 minute walk to line 1, station Museo) or by bus (204 or 168 were the lines we used to get downtown).
Awesome place!