The apartment: The apartment is one of the biggest and nicest ones I've stayed at in Europe, and much larger than in the pictures. In fact, the pictures don't do it justice. It has floor to ceiling, double-paned windows in the common room, an open kitchen that looks out into the common room, 2 full bathrooms, and split bedrooms on either side of the apartment. This allows for privacy despite the bedrooms being a lofted style with no doors. There is rustic furniture and tasteful art throughout the space, unlike most European apartments that are just full of Ikea furniture. The only downside was that the internet was only accessible in the common room, but I didn't really mind since I was on holiday. :)
Neighborhood: The apartment is in a more historical part of town and within an easy 10 minute walk to the town center. There are plenty of late night bars and restaurants right out the front door. I'd recommend trying the falafel salad at the kebab place around the corner for a midnight snack and getting the arancini and sfogliatella for breakfast from Scaturchio, a famous bakery 5 minutes away. One pro-tip would be to bring some earplugs - the apartment faces a university and overlooks a piazza which can get pretty loud through the night but the double-paned windows and some earplugs were enough to sleep soundly through the night.
Host: Giuseppe was the most considerate host! I was his first guest on Airbnb but he seemed like a pro. He was very responsive to all my questions, left us some limoncello and bottled waters in the apartment, and was kind enough to drive us and our luggage to the port to catch the ferry to Capri.

I would contact Giuseppe in a heartbeat the next time I visit Naples. His apartment is a bargain!