Positive: The flat is really nice, very big and well equiped. Very nice area, with a nice piazza with all shops (supermarket, bacery etc.) an restaurants just around the corner. Nice view on the Tevere! Walking to the centro storico or to Trastevere is no problem. Checking out time was very flexible.
Negative: There is quite a lot of traffic, so it is not the quietest place. However, with the windows closed it was no problem for us. The mattress is extremly soft and seems to be very old (not dirty but very used) , so we would not recommend it to people with "back problems" - maybe you could use the a sofa/ coach instead. We did not meet Fredrika because she was not in Rome. She asked somebody from an agency to meet us and to give us the key for the flat. At the end everything work out fine. However, she did not inform us about her absence herself (what I would have expected), instead we found out only a day before we arrived in Rome and had to make a few phone calls and contact different people to arrange a meeting.