It's a nice place to stay. We were staying there for 2 weeks and it was comfortable.
It's located not in the city center, but it's close to the metro station. You can reach any place in the city center in ~30 min(way to metro station + metro). When we were not too exhausted in the evening, we walked home by feet and it took less than 1 hour.
The flat is well equipped(from toaster and coffee machine to washing machine and dishwasher). It's roomy, with a large balcony. In addition, the view from the balcony is picturesque, especially at sunrise time. You even can see mountains on background.
Giuliana was kind and friendly. It was easy to communicate. Also, she provided some food for breakfast. It's very convenient when you check-in late(as we did).
24/7 supermarket is located in ~1 km. Another supermarket which is working at day time(something like 08-21) is located in ~500 meters. And you can find all the necessary stuff for cooking in the kitchen.
And my personal recommendation if you stay there - visit pizzeria at Piazzale Siena, 8. It's about 15-20 minutes by feet from home, cheap and tasty