The apartment is really nice, bright and clean, with a good bed and a large shower with plenty of hot water. It is well located in the Monti district, close to numerous restaurants, and an easy stroll to the Colosseum. Close to the Termini station also, which is quite practical if you have to catch an early train or bus to the airport. (Bear in mind that for the 7 o'clock flight the first fast train leaves too late, and the station may still be closed as it was our case, so you'll have to take the bus and give yourself enough time to walk around the block instead of just crossing the station).
The Via Cavour is a busy street, so if you're a light sleeper, perhaps bring some earplugs, but traffic tends to calm down around 1 o'clock.
The flat is on the 3rd floor without elevator, so pack lightly!
Piera was really nice, agreeable and flexible with the check in and check out time, and didn't make any fuss when we arrived 45 minutes late due to the bus being stuck in traffic. A nice host. Recommended!