Carmen's flat is lovely - cosy, comfortable and clean. She was very communicative leading up to our stay and we were given some really useful tips for places to go in the city, as well as a few discounts at local restaurants. I was also delighted to see Carmen had a Bialetti stove top coffee pot, which I have at home - I appreciate those sorts of comforts.
The flat is about a five-ten minute walk to Termini, from where you can get to a lot of destinations in the city either by metro or bus.
One thing to note is that the second bedroom is on a mezzanine level, so the ceiling is quite low. It was fine for my friend and I, but anyone taller than me (I'm about 160cm) might find themselves having to stoop.
All in all, a really great experience.