Perfect place, perfect location.
You really do see di Trevi from the window, apartment is really spacious, we were 4 people and used just the two bedrooms, which was perfect (there is a third double bed over the living room). Be aware that you can hear the fountain all the time (sounds like heavy rain with windows closed) and the occasional applause. Fillipo is a great help and lives downstairs, which is convenient for check-in/check-out