The host, Carlo is very sweet, accommodating and responds to messages quickly. Like everyone mentions, the location of this apartment is ideal! 3 min walk to Piazza Navona, 10 min walk to the Pantheon, 10 steps away from Campo de Fiori.
The studio is small but everything you may need is provided for. The curbless shower (the floor space in front of the sink was the same place where you stood when you showered) was a new experience for me. Everything was fine, except the excess water took longer than I would have liked to drain itself. I had to mop the excess water with a provided mop after every shower.