The hosts are very nice and extremely helpful. The pool is great (albeit a bit cold for this time of year, but that's the case everywhere). The apartment has most of what you'd expect. The bus to downtown is very easy and convenient, the metro station is a bit of a walk.
We were a bit disappointed about the noise levels in the unit, but it does heavily depend on your neighbors. There is virtually no noise from the road though. Overall a decent place to stay to visit Napoli.