Wonderful apartment in a really lovely neighborhood full of great restaurants and quirky boutiques. Pretty easy walk to/from train station and all central sights, and right next to subway stop for easy travel to Vatican. Rooms are quiet and comfortable. Host is very responsive.
One thing to be aware of is that there isn't really a "living room"—just a small breakfast table in the front hall/kitchen. The pictures are accurate but we didn't quite realize this until we checked in. It was a bit tight for our group of 5 to gather together outside of the bedrooms.