The appartment was great. There were 3 balconies, which we enjoyed very much. Federico and his partner (I assume) were so nice at the check-in and helped whenever they could. The heat wasn't on and I texted Federico how to do it - he came over himself and put it on! Also, when we had to check-out at 10am but wanted to go see the "Ercolano" (very recommendable btw) they took care of our bags until 3pm (!) so we could go there without any stress. Later, they brought it to the trainstation. They are like your napolitanian mum & dad. Also the Appartment is great. Huuuge bedrooms and, as i mentioned before, the balconies really are something.
Neighborhood is okay, but don't underestimate it. Nothing will happen to you, but keep ur bags close. :-)