We had a really great stay in Fiamma's well located apartment. It's a 2-min walk from the Vatican in one direction, and Castel Sant'Angelo in the other direction. The apartment is comfortable, the beds were really cosy and having three toilets and two showers was a bonus for our family of six. The big bedroom having two single beds and one double is great for larger families.
The master bedroom has a lot of furniture so not much space for large suitcases in the room.
The kitchen facilities are basic, which was fine for our stay, but if you're a keen cook you might find the simple invection stove top and no oven a barrier.
The apartment was really clean and we'd definitely recommend it.