This is the perfect base to explore Trastevere and the rest of Rome, the location is superb and everything is within easy walking distance.
The bed is comfy, the double glazed windows keep out the street noise, a/c works if you need it. Everything was just right for our 4 night stay in this buzzy neighborhood. There are so many restaurants just seconds away from the flat, (including one with a carbonara making course) we were spoilt for choice.
The reviews are correct, the shower is quite small and the hot water doesn't last that long, but neither of these were issues for us as the place is perfectly clean and comfortable and it's a very characteristic old building.
I would definitely recommend this place highly.