Absolute recommendation!
Very central and close to bus and metro station. Also, you can just walk down Via Toledo (very nice for shopping) and at the end of it you're at the beach!
The room itself was perfect, spacious with a cute little balcony to the piazza. I read recommendations that it would be loud at night, but honestly we had no troubles with that at all. It wasn't very loud and even if it feels like it, you can just close the balcony doors.
The room has airconditioning, which is great.
The check-in was easy and even though Teresa only speaks Italian, it was clear what she wanted to say and explain. Teresa herself is a very lovely and super friendly lady!
If you're travelling to Neapel, Teresa's apartment is the best place to stay at!