Andreas, the owner, was perfect. Really reactive, he gaves us very good advices and all information necessary.
The flat, perfect, is located at 5 min by walking from the Pantheon and Piazza Navone. And 30 min (walk) from Vatican and Coliseum.
All our movement during the trip have been done by walking without any problem.
The appartement is located in a neighborhood and building really sure and plaisant.