Excellent location, 500 meters from the metro station (Mergellina, line 2), which is just 2 stations away from the city centre (Montesanto station). Also, close to the beautiful Naples quay, where someone can go for a stroll. It is worth noting that coffee and sweets are cheaper and better in the area surrounding the apartment, compared to the touristic areas. Moreover, the apartment block seemed very secure, with a 24-hour security guard present. Lastly, Giampiero was always asking if we need anything, ready to solve any issues we had (for instance, there was an issue with a noisy neighbour).
P.S. If you are visiting Pompeii, please be aware that there are scam "tourist offices" which are phishing out tourists from the moment they get out of the train.