We had a group of 9 and the place was perfect for us! You could fit up to 11 because there is a pullout couch that we didn't use. The place was very clean and what we expected. The host even let us drop off our bags before the check-in time which meant we didn't need to leave our stuff in the car while exploring the city.
Our only issue was that we didn't know the washer/dryer was a combination and took about three hours to do one load. It was a bit confusing for us to use at first but the host was very responsive in helping us with this and any other concerns. They even left complimentary water, coffee, and wine bottles for us!
The city is walkable distance if you want it to be, about a 30-40 min walk to the Vatican and other main attractions. Some are further, but this was really great. There are a few cafes to get breakfast nearby. The area is not very touristy, but this meant it was quiet at night. Free street parking which was easy to find, right outside the apt most days.