We stayed here for 3 nights. Costanza wasn't able to meet us to check in but her mum showed us everything which was great. Excellent location - not far from Trevi Fountain and Spanish Steps. Comfortable bed and good air conditioning.
Only downside was that the water for the shower was very temperamental. I had to have a cold shower on at least one occasion. We did inform Constanza and it worked for one evening but unfortunately the next day it did not work again.
Would also be a nice touch to have some pretty flowers on the balcony - the ones at the moment are very dead!
Overall very good location with responsive host, but you will have to compromise on the shower!