I quite enjoyed my time with Roberto. After initially having trouble finding the place (more to do with the 36hours travelling than anything else), I was met by Robertos brother who let me in, gave me some keys and a beer and let me get settled! Then I was free to come and go...
Roberto was a very welcoming host, the apartment was very clean and very comfortable (loved the balcony!), there were some excellent places to eat close by and the nearest metro station was only a short walk...
I wholly recommend Roberto's apartment if in Roma...!