Superb location a stones throw from Fiori (good windows that largely insulate from any noise). It's also just 5 minutes walk over the bridge to Trastevere with it's attractive restaurant scene. The apartment was very well equipped and had everything we needed (including a large Smeg oven for anyone who likes to cook!).
I felt the place could do with a little investment (e.g. the shower wasn't great, and some of the old world feel was just a little too close to the bone, for my taste at least). But overall I'd recommend this place and in particular the reliable and attentive service provided by Andreas. He provided us with a map on arrival and gave us a great overview of Rome and how to get about. He also allowed us to arrive a little early and store our bags while the cleaning staff worked on the apartment.