Our family of 5 (two adults, two 7 year olds and a 2 year old) happily stayed in this spacious, clean, modern apartment for 4 nights. Centrally located, overlooking Campo de'Fiori (great little market) and within walking distance to all major tourist sites.
Andrea, our host, met us on arrival and walked us through the apartment and its amenities and provided a map with local points of interest/ supermarket/ good family restaurants etc. He also made himself available throughout our stay for any additional questions.
Two things to note:
1) The apartment is up one flight of stairs. That said, there is a large entrance hall so you can leave a stroller/ bike there rather than carry it up and down.
2) The kitchen and one of the bedrooms overlooks the square and is directly above a (very good) cafe/pizzeria. It is a beautiful vista but as we have young children and we had been sight-seeing all day, we were absolutely exhausted by 8pm and were typically in bed early. There was noticeable noise from the cafe until 1am every night which made it difficult to fall asleep, and then the vendors from the market would be setting up their stalls at 7-8am. If you are a light sleeper I would recommend bringing earplugs.
All in all a great apartment though and we would certainly stay here again!