We stayed for a few days with two children (2yrs and 4 yrs) and loved the place. It really felt like a home.
Nando was able to check us in at 10.30am due to our early flight, he was really quick to respond to questions, sent us tips and kindly left us some fruit and coffee for our stay. The apartment had toys for young kids and the TV with Amazon Prime had cartoons the kids loved.
The location is close to the station, which was 10 minutes walk, so the apartment was a good base to explore Vesuvius and Pompeii. Plus it is just by the old town, so access to restaurants was easy. Apparently the area near the station is not meant to be the nicest in Naples but we had no problems and felt like we were staying in a real Naples neighbourhood. As it is off the main road, it was really quiet.
The second bedroom is on the floor below the main bedroom, but we could hear the children when they woke through the floor, so the distance was not a problem. There was a bed next to the main bedroom too, which is an option if you do not want to be too far away from children. The air conditioning is effective throughout, so sleeping was very comfortable. Comfortable beds too.
I would really recommend this place. The only negative is the three floors you need to walk up to get to the apartment. However, a pulley system is installed to get luggage upstairs. A great touch and the walk up is not that bad when you get used to it!