Roberto and his charming dad (who met us and showed us the room) were great hosts, and the view from this flat is incredible. Close the shutters for a great night's sleep, then step out on the balcony in the morning to see the sun rising over Vesuvius—glorious!
The best touch, though, was that in the entryway of the flat was a secure place to leave our bags for a few hours after we'd checked out, and some extra sets of keys. This saved us having to locate/decipher the luggage storage at the nearby train station, and thus gave us more time to explore on the day we checked out.