We've a family of 4 (kids ages 12 and 15) and we've stayed for 5 days.
The apartment is great for a family (two separate bedrooms) and its location is perfect: 5 - 20 minutes walk from most attractions. The apartment is clean and very well maintained, with a very nice roof and balcony. Flaminia was there when we arrived and was very helpful via email / SMS when we needed more info.
Please note however that the flat is on the 4th floor without elevator, which may be an issue for some. Overall great experience and will defiantly use again.