We stayed at the Coronari Apartment for almost a week mid December. The flat is perfectly located and ideal for walks and rides to any Rome attraction. Francesco was very helpful, responsive and all went smoothly. We got the key on time and were explained our way around very kindly. I can only but recommend the host and the flat.
On the downside, the flat is "really" located on the 4th floor of a beautiful old roman house. If you have luggage and are not extremely fit I would not recommend the exercise. The cooking tools and plates are quite old and not really practical. One main issue to beware of is the fact that since the building is ancient the pipes are not fit and you may end up having to pay extra on plumber or even a handy man since the locks and doors need some upgrading (my daughter got locked in the bathroom for 2 hours - which was rather embarrassing since it was either braking the lock or ...). One last thing the bed downstairs is hard and not really designed for long stay.