Marco and his wife are incredibly nice people with great English, making communication a joy. They are both lovely and so helpful. Their place, which is very clean and modern (with a shower my husband adored!) is located near a fantastic outdoor market- one of the biggest in Naples- and great for food shopping as well as other items. As a person with celiac, I also appreciated that less than a five minute walk away is a terrific bakery called Rescigno with its own gluten-free section. It's also very close to Via Duoma and Via Tribunali, two major streets with lots of interesting sites. We were able to walk almost everywhere. We walked around at night but I don't know how a woman alone would feel as the apartment is on a dark alleyway.
Be prepared that Centro Historico is very dirty, as are other areas in Naples. Personally, we loved the city and its many layers but if garbage bothers you, then you will have a problem in this terrific city. If you learn to see beyond that, you are in for a real treat. Naples is a fascinating city we already are longing to return to and Marco's place will most likely be where we'll stay again, very happily!