We stayed in the two bed apartment which is separate from the rest of the hotel, and has its own entrace on the 2nd floor (there is a lift). We were given codes for both the main door and apartment on check-in. Check-in was smooth, and the staff were friendly and helpful.
The location is great - we were able to walk to all the attractions on our itenary, including the Pantheon, Trevi Fountain, Spanish Steps, Colloseum, Palatine Hill and Vatican City - and many amazing buildings. There are also plenty of shops, restaurants, cafes and icecream places. We found walking around Rome as tourists very safe with plenty of armed police visable (possibly due to it being Jubilee year).
The apartment was was clean and spacious, with the only minor negative being a small amount of noise from the road outside from one of the bedrooms. Each bedroom as its own onsuite with good water pressure, and both can be locked with a physical key provided.