Andrea was a very good host, helping us quickly whenever we had a problem. The rooms are all almost the same, very tidy and simple but beatiful in decoration.
Rooms have a nice view to the market square and we enjoyed seeing the local life, but unfortunately during weekend nights the square turns into youths drunken playground and it was very loud. So I recommend taking earplugs with you. During the week there was no noise problems.
All in all I would recommend staying with Andrea. Location in Trastevere is very good, surrounded by many restaurants, not too touristy, nice walk distance uphill to the viewpoint where you can see the whole Rome.