The apartment is a real jewel in the heart of Rome. It is very near to the center station, but yet very quiet.
There are plenty of restaurants and supermarkets nearby and most of the monuments can be easily reached on foot (Colosseum/Altare della Patria/Piazza Navona: 30 minutes). I suggest the Trattoria da Dino which is only 5 minutes away :)
The apartment was very clean and there is everything you could need. The check in went smooth and Ariana showed us the apartment personally, she's very kind and helpful and made us feel at home.
I would definitely recommend this apartment and I'll definitely book it again the next time I'm in Rome!