Our stay at Campo de Fiori was a mixed experience. The location is great. The host was (although away from town) quick to respond to our messages but rather unpleasant in his ways and difficult to communicate with.
Unfortunately we were quite unlucky with a few things. There was no internet connection during the 7 days of our stay. It can be the old street or a bit of rain, but the fact stays the same - no internet. The tv cable didn't seem to work either (not that we needed it, but there were two tv screens with no working cable).
We lost access to the bathroom for 21 hours. If you turn the key halfway and close the door, it locks. The owner was more busy claiming that we had damaged his property (which we hadn't) and how much it would cost to fix it rather than actually fixing it. Imagine: you have two small kids and no toilet access the entire night.
The kitchen facilities are also poor. The Nespresso machine (and the provided coffee) were great, but the cooking gear is inadequate (f. ex. there was no proper knife). There is no place to sit down and eat either.
The whole apartment is more like a hotel room with a washing machine (which can in fact be useful). It consists of two levels with one bed and a couch – there is no privacy, you cannot close a door - it’s fine for two people, but too small for a family with two children.
So my advice: be careful with the bathroom door. Do not bring small children with you, don’t rely on own cooking or don’t stay here if you are a family of four. Do not rely on having internet or tv either. Otherwise it's ok.