Carla and Ilaria are super sweet! Ilaria was very helpful with check in and any questions I had during my stay. I didn't meet Carla until my last night, but she was very good with communication prior to my arrival. The flat is very close to everything; if you don't mind walking, every tourist destination (except Vatican City) is within 2mi/3km. The neighborhood has many restaurants to choose from as well.
The living room and loft are both very spacious. The loft was shakier than I expected, though it was secure. There's a nice patio area to relax in after a long day exploring.
The bathroom is quaint, but the shower is a bit tight. I'm 5'4, 145-150lbs, and it required some careful maneuvering to shower (though to be fair, I am accustomed to spacious bathrooms). The front door to the building sticks; I would spend a few minutes every time looking like I was trying to break in before getting the door to unlock. WiFi is also spotty, but my friend says WiFi in Italy leaves a lot to be desired.
You MUST have and/or love cats. One of the cats barely condescends to look at you, but the other is super friendly, and will try to play with you a lot. They have free run of the flat; I have more often than not come back to find the friendly cat lounging in my bed. It even tried to sleep with me one night. You will also get cat hair in places you didn't think were possible.
Carla and Ilaria are wonderful people. If you can overlook the cats, I would highly recommend their hospitality.