We stayed at Simone's and Martina's apartment for one week in April 2015. Simone was very kind and would be there for every question we could possibly have. The apartment was clean and tidy. There was even a cleaning service every day! It's located very central (only 15 minutes to the colosseum by foot) . There's metro station and a bus station only a few minutes away, so we reached everything in a reasonable time.
We highly recommend this apartment!