Excellent location, apartment is a stones throw from the Trevi Fountain and walking distance from most attractions. The apartment was clean and had everything we needed. Would recommend for anyone wanting to be in the middle of the hustle and bustle of Rome.
We were offered lots of help, for example arranging transfers from the Airport, which was perfect. They also offered to book attractions.
A few minor things to note is that the 2nd bathroom does have a low ceiling, which did cause a few bumps, we avoided using it in the end. The apartment is on the 5th floor, there is a small (2 person) old style lift, which worked most of the time, but when it didn't, the walk upstairs was quite a trek. Other than that, we had a pleasant stay.