My wife and I stayed at Chiara's place during our time in Napoli on our honeymoon. The weather wasn't quite as clear as it might have been, but we could make out the outlines of Vesuvius and Sorrento out of the windows and could see the entire south end of the city. The only better view we had was from the castle on top of the hill, which is hard to beat.
One important note that wasn't a problem for us, but could be for some travellers, this is at the top of 6 flights of stairs and there didn't appear to be an elevator. If you're young and don't mind stairs, this isn't a concern. But, if you have issues with something like that, you may not have the same experience we did.
The apartment itself was well appointed with a beautiful living space. If you're looking to stay in and watch netflix all day, you'll be disappointed, but we didn't even turn on the TV. The location is in the center of basically everything which was the main draw for us. Coming from the US, the graffiti everywhere was a bit disconcerting at first, but the area couldn't have been safer. There is access to both Line 1 and Line 2 of the metro minutes from the front step, which will get you anywhere you want to go in the area.