We had a great stay at Antonella’s place! Her colleague was waiting for us outside when we arrived, and helped us carry our luggage up the 3 flights of stairs. The place was exactly as described. As others have said, the location is great, very close to both Campo de Fiori and Piazza Navona. We really recommend trying the Frigidarium for gelato and Cul de Sac for wine/appetizers, both less than a block away. We also walked to the Pantheon (10 minutes), the Trevi Fountain (15 minutes), Trastevere (20 minutes), the Vatican (20 minutes), the Spanish Steps (20 minutes) and the Colosseum (30 minutes).
The only negatives were:
The bed is quite hard; we both woke up pretty stiff in the morning.
There is no soundproofing on the ceiling, so we heard very clearly a woman walking around upstairs in what I can only assume was heels at all hours - very early in the morning, during the day, and late at night, waking us up a couple of times.
Also every afternoon for the five days we were there the neighbors in the courtyard blasted an ABBA album from about 1600-1900 each day.