There are two main reasons for my rating. One is the apartment itself. It is lovely. Spacious and with many amenities: a comfortable couch; a dining table and chairs; a smaller table that can function as a desk; more than enough room/storage to unpack;a fine clothes washer; tasteful furnishings; etc. In addition, the bathroom is a treat. If you've ever tried to balance a toothbrush, toothpaste, sunscreen on a small bathroom sink, or to turn around in a miniature shower, you will definitely appreciate this bathroom. There is an actual counter that the sink is located in, so that it's possible to spread out all of ones usual cosmetics, etc. in one place. And if that's not enough space, there are also shelves--and a magnifying mirror! As the piece de resistance, the shower continues to deliver hot water whenever you need it (in contrast to some other rentals we've stayed in where the hot water stops after 3 minutes).
The other reason for my rating is the location: it simply cannot be improved on. If you look at a map, you will see that it is at the center of everything. A few doors away is a small plaza with an actual 16th century fountain. Granted, not as large as the Trevi, but with running water and much, much closer! :) The plaza around the fountain also has several restaurants where locals eat and that serve good food and have friendly waitstaff, some of whom speak English and all of whom are patient with customers who don't speak Italian.
Other aspects of the location can easily be seen by looking at a map of Rome: the apartment is almost exactly in the middle of everything you might want to see/visit. Within at most 20 minutes in one direction, you can be at the Colosseum, the Forum, Trajan's Market, the Victor Emmanuel monument (which has some interesting exhibits); the Pantheon; Piazza Navona; several small museums; Torre Argentina (and its cat sanctuary); etc. Medieval churches seem to be on every second corner. There are also super markets, clothing shops,etc. In the other direction, you can cross the Tiber and be in the Trastevere neighborhood, a wonderful area to wander in (one of the oldest in Rome) with charming cafes and restaurants. Cross the Tiber using a different bridge and you will be in Vatican City with St. Peter's and the Vatican Museums and near Castel St. Angelo, etc.
But if you don't feel like walking and want to say in the neighborhood, that too will be fine. The heart of the Jewish Ghetto is about a block away with both kosher and non-kosher restaurants. In addition, the street (Via del Portico di Ottavia) ends with the ruins of the Theatre of Marcellus. There is something very special about eating dinner or having a gelato while gazing at some ruins that are actually in a fairly good state of preservation. If you walk in the other direction, there is a wonderful restaurant that serves Neapolitan food (Rosso Pomodoro) about two blocks away (on Via d. Torre Argentina, across from the west side of Torre Argentina). Two blocks farther on is the church of Santa Chiara, which has live concerts on many days of the week.
I cannot stress too much how amazing the location is. Indeed, I get carried away writing about it.
Lovely apartment, amazing location--what more can one ask for? We look forward to returning.