Perfect location! You can walk easily everywhere and if walking is hard, there are a couple taxi stands almost at the door ... less than 10 minutes ride to Vatican, Coliseum, train station, etc. Really close to restaurants and shops.
The apartment was really clean and it was perfect for 3 adults. There are some stairs to get to the bathroom and to get to the lift/elevator, so have that in consideration if mobility issues ... but besides that, I would definitively recommend it to anyone planning a Rome visit.
I am planning on going back with my parents in April and I hope the apartment is available :)