We communicated with Giuseppe (not Vincenzo), who let us in the apartment and was point of contact for our stay. The apartment is great for up to 5 people or 2 couples + and also very well connected. Unfortunately the wifi didn't work and we were not told upfront, which was somewhat annoying as I had some work to do. Still had a great time in the place and would come back, if the internet worked. ;-)

Also there is a tourist tax paid in cash of €3 p.p / night that I wasn't aware of, but is standard in Rome.