We loved staying at Marco's place. There are so many pluses. The place is on a walking only street with tons of restaurants on it. The location is amazing and you can walk everywhere - 5 min to St. Peter's, 10 min to the Vatican museums, 20 min to Trastavere. The apartment is large and comfortable, and despite being at street level, you get so much privacy because of the solid windows. Hostmaker does a very good job of being responsive, we used to get almost instant responses on Whatsapp to queries.
The only mildly negative things I'd point out are that the wireless signal would drop from time to time (a very minor inconvenience) and the shower is super small. Neither of these would stop us from staying at the place again.