We had a great time (5 days) in the apartment. The apartment is small but very modern, clean and well equipped. Check in process was easy and well explained. Communication with Andreas was fast & easy. The location is great to discover the city, and we could walk to all major highlights (e.g. Vatican in about 15min walk). Trasteverre has great restaurants and bars; but as the kitchen is well equipped we used also the apartment for dinner sometimes. Very nice is the small Bialetti Coffeemachine for making strong italien coffee on your own ;)
The balcony/terrace is in front of the apartment (not directly in the apartment) but nevertheless is a nice place to have a glass of wine outside after a long day in the city.
We can highly recommend the apartment for a stay in Rome!