The apartment is an excellent solution for people who expect prime location, high standard, extraordinary architecture and style. If you want to "feel" the old Rome- this is a good choice for you and it will make your stay in Rome very special.
2 minutes walk to metro station, 1 minute walk to the Spanish steps. Close to Galeria Borgesee and Borgeese Gardens. Vatican can be reached in 15-20 minutes (including walk from metro to St. Peters).