We stayed 3 nights in Sally's apartment with 2 kids (11 & 14).
After a very warm welcome (thanks), including a range of basic supplies (again, thanks), including guidebooks and advice. Great hosts.
We found the apartment was easy to get to from the airport, and close to public transport, especially the number 8 tram (centre) which was sometimes very crowded. The number 3 tram (colloseum) also seemed promising, but we did not use this. The nearby Sunday biological market in Testaccio was excellent, and the flea market on Sunday was enormous!
We found the apartment very comfortable and light - easy to live in. With the windows shut and AC on it was cool and quiet at night.