This apartment was perfect for a large family vacation. I booked this location for a group of 9 adults (all extended family), and it was great. The setup is one in which there are separate units, all connected by a common hallway. The first unit is like a studio space (bathroom, kitchen/living, and bedroom), the second is a dedicated 1-bedroom, with a pull out couch in the living room, and the 3rd is the largest with 2 bedrooms (1 with a queen beed and en-suite bathroom, and the other with 3 twin beds), a full bathroom in the hallway, and a living room/kitchen (with a pull out couch). The apartment overall was clean and comfortable, and the location was incredible. It's right down the street from the metro stop (less than a minute walk), and about a 10-15 minute walk to the Vatican. There are plenty of cafes and restaurants within a 10-minute radius as well.
Communicating with the host's proxy was done via WhatsApp, but I was a little stressed day of check-in, because I didn't receive any messages regarding instruction on username/number until about 3 hours before, so I didn't know if there were any specific instructions and/or directions on picking ups the keys. I didn't want my family to be stuck outside in the pouring rain while I was trying to figure out directions on how to get inside the apartment, but it turned out not be be an issue--just me being overly cautious. When I arrived at the apartment, there were bags of trash that were sitting in the hallway of the unit, and I was told that due to it being Sunday, the trash removal would be the following day (side note: it was never picked up), but other than that, the apartment looked just as pictured and relatively clean.
The only thing to make note of is the elevator/stair situation. There is a small elevator that can be used, but it's rather cramped and claustrophobic, and I wouldn't put more than 3 adults in it max (even with 3 adults, you'll be very cozy with one another). That being said, there are 2-3 flights of stairs to go up and down, so it's something to take into consideration for anyone traveling with those that might have physical difficulties and/or those with small children. I didn't feel that the stairs detracted from the location or apartment though (just something to keep in mind), and all in all, my family and I had a great stay!