I spent only two nights in the apartment with my mum, and then my sister replaced me as I was sleeping at an Italian friend's house nearby.
We were warmly welcomed by the lovely Isabelle on our arrival.
She was very kind and particularly helpful concerning the things to know about the city, where to go, where to go buy groceries and had lots of good advices to give.
The apartment is very comfortable and fits the description and photos. It is spacious, nicely put and decorated, and everything functions well.
We had a few requests (as it was very hot, we asked for some fans and one of the Moka pots was broken) that were quickly responded to by the owner of the apartment himself.
He arrived at the apartment without warning, though, and we had to stop what we were doing for a time while we helped him (we offered to) build the fans and wait for him to go buy a missing piece in one of the Moka pots. But he was very nice and though we would have prefered to be warned at least an hour before, we were glad we got all those things fixed up.
One or two things to know, though: There are very light curtains, and no stores at all. The sun comes into the apartment early in the morning, so be warned, late-risers! In a city as sunny as Rome is, it can be annoying if one wants to sleep after 7am.
On the day my sister and mother left the apartment, two or three persons entered the apartment, before 11am, to clean it. They acted quite cold (no smile, no "hello" or explanations whatsoever) and my family felt kind of kicked out, especially since none of them spoke good Italian. Luckily, an Italian-speaking friend of mine came to their rescue, but we would have prefered those people to arrive at 11 am, though, as planned.
All in all, we had quite a nice time in the apartment. The location is perfect (really near the Colosseum and in-between two subway stations)