Flat: it's cozy and clean. A note to keep in mind: there are 2 small windows which don't provide a lot of natural light but we didn't have any issue with it.
Amenities: there were a lot of small touches that made everything great - there was a charger for an Android phone, several adapters, cotton pads for your face, shower gel and shampoo, 2 umbrellas (very useful since we didn't expect it would rain as much as it did!)
Location: perfect! The flat is located close to Piazza Navona and you can easily reach the Vatican, Piazza di Spagna, the Colosseum and Fontana di Trevi by walking.
Hosts: they were great! We arranged an airport transfer with them, so there was someone waiting for us there. There was also someone waiting for us when we arrived at the flat and that person explained to us everything we needed to know. They also left a folder with suggestions for places to visit, restaurants, etc. And they were sending us regular messages with reminders of what was next (when we needed to check out, etc.)
All in all, we had a great experience! Thank you, Barbara & Fabio!