The apartment is perfectly located inside the triangle created by the Mapocho river and two big streets - Av. Grav. Velasquez and Av. Libertador Bernando O'Higgins. Everything is superclose so you won't need any transportation except feet at all.
It was really easy to check in an be in touch with Carolina. She was helpful and organized the check-in in the most comfortable way.
Taking about the apartment itself, I'd say it needs some small improvements. Some overall refreshment and some basic things that create comfort at home such as more dishes, kitchen chairs...