We stayed in this apartment for 5 days and it was fantastic!
The location was great, off the busy Via Del Corso but at the back of the building so there was no traffic sounds. It's also close the Spagna metro station so it's really easy to get around Rome and walk to the Spainish Steps, Trevi fountain and the Pantheon.
The apartment is just like the photos, light-filled, spacious, clean and very comfortable - like a home away from home. Denia was very responsive to my messages in the lead up to the stay and Andrea let us in and was very friendly and helpful while we were there. He gave us a pack of information with restaurant recommendations, which we appreciated.
The only thing was that the internal walls are thin so if you have a noisy family staying next door, you will hear the screaming children at times. Other than that, I would highly recommend this place to stay in, it was great!