I can't really get over how amazing this location is; it's right in between Campo D'Fiori (markets, eateries, bakeries) and Piazza Navona with a huge variety of restaurants/shops/wine bars, just steps away from the building. There's also a taxi station down the block and 8 different buses that can get you around Rome right out front. Most notable restaurant/gelato place near by were Frigidarium (MUST!) and Cantina & Cucina (solid!).
Antonella's place was literally walkable to almost all parts of Rome - wife and I walked to the Vatican (15 minutes), Pantheon (6 minutes), Piazza Navona (2 minutes), Campo D'Fiori (2 minutes), Colosseum/Roman Forum (20 minutes), Trastavere (10 minutes) and even, Borghese Gardens (30 minutes). Only place where we had to take the bus was to Roma Termini (primary train station, but the bus #64 is right out front which costs you 1,50 euros, about 20 minutes).
Amenities wise, there's a washer (no dryer, seems typical for non-US, but does have clothing lines to hang your clothes to dry), dishwasher and full kitchen. Bathroom and shower was a little small but was modern and clean. WiFi was a little slow, but worked OK for the most part.
Only thing to be aware and note is that it is on the 4th floor with no elevator (it's technically 3rd floor because the ground floor is not counted). We had no issues with this but may be a consideration for certain travelers.
Overall, we enjoyed our stay, we would recommend it to any couple traveling to explore Rome. Antonella was helpful in giving recommendations for activities and restaurants; she was also helpful in setting up rides to and from the airport, pretty responsive to messages, and was nice of her to gift us a bottle of Chianti for our stay! We definitely recommend staying here and would stay here again.