We stayed at Simone's 5 nights and it was great. It is perfect for 2 persons with the bed space upstairs. Kitchen is well equipped.
The location is great to visit, in the heart of Trastevere. I would just mention that it is extremely noisy at night, especially on the weekend.
The communication with Simone was great, he was at the appartment to welcome me, which made the check in very easy.