Stop searching. Close your other tabs. This is the only place you should be staying in central Rome. This apartment is beautiful (the pictures don't lie), historic (900 years old!), and PERFECTLY located (draw a circle of radius 20 minutes walk, and you will cover every major attraction in the city). Valerio himself is the epitome of a super-host, taking the time to walk us through an amazing array of local advice for our stay, even annotating everything on a map that we referred to throughout our visit. We would happily have lived there forever, and were incredibly sad to leave.