I had a wonderful experience staying in Francesco's flat. The location is great - the neighborhood has plenty of restaurants, is well connected by transport (though it's a very easy walk to the heart of town, about 15 minutes), clean, and very central, but just outside all of the craziness of the very centre. It's a surprisingly spacious room and the futon is quite comfortable and easily big enough for two. But the biggest plus to the place is the host! Francesco is an absolute gentleman who went above and beyond to make me feel comfortable, at home, and make sure that I got the most out of my experience in Rome. I'm only sorry that I didn't get to know him better than I did.
A great find! I'd recommend it to anyone planning a visit.