We stayed at the apartment for 5 days and i can only say the flat itself and the location were perfect!

We were greeted by Ari, who explained everything for us and provided us with some written down assistance in the way of maps and guides. The flat was extremely clean a very good size for the 2 of us (although I understand it can sleep 4-which wouldn't be too much of an issue). The bed was very comfy with sufficient blankets and covers etc and the room was very quite, even if the flat is located in such a central area.
Monti is and incredible place, full of cafes and restaurants and at walking distance from all major touristic attractions.
I recommend this apartment, and if we will back to Rome i hope i will be able to stay there again!