The flat is great. Guendalina is a fantastic and very flexible host.
The flat is easily reachable by train from the airport or Roma Termini.
We loved the roof-terrace in the evenings.
The area is quite and restaurants and shops are in walking distance. By tram or bus you are quickly in the city-center - but you can walk everywhere easily (we did to e.g. Vatican in 45, forum romanum in 35min.)
We can highly recommend this flat and will come back!