Great place. The location is great - very close to Pantheon (10 min walking), Trevi Fountain (10 min walking) etc. The choices for eating at this location are also great (just walk downstairs and you have a range of choices from main course, to dessert).
The place is on the 4th floor but worry not, there are elevators to take you up. Also, I found the host to be very accommodating and very communicative.
The wifi speed was also pretty good.
The house was well furnished with essentials for cooking (oil and salt, plates, plans etc). Since we visited in December we wanted heating and the heating was very effective. Hot water for shower was great pressure and also great temperature. We were a bit worried about noise at night but the place was not noisy at all.
Don't miss the Two Sizes Tiramisu shop downstairs and the Limoncello boutique 10 meters away.