Our stay at Carlo's apartment was very satisfying. Just a short walk to the Colosseum and bus stops, with all sorts of restaurants and needs such as ATM, supermarket, etc. All of this is shown on a map on the door Carlo has prepared, which also has all necessary information to keep life convenient.
He greeted within 10 minutes of contacting him once we reached the apartment, and helped us get our luggage up the steps to his apartment on the 2nd floor. The rooms are just as described. The apartment is equipped with AC, but we didn't really need it even though we visited on hot days, since the breeze by opening the windows was sufficient to keep things cool.
The side with two rooms are indeed a little noisy, but it was all expected from the reviews I had read prior to booking with Carlo. The noises were minimal with the windows closed and died down around midnight, and we were up til that time anyway so it was no inconvenience at all.
Carlo is very helpful in offering to call taxis and will answer any questions very quickly.
Thank you again, Carlo!