This apartment worked well for our family of 4. It does not look like much from the outside but it is quite nice inside. The manager was waiting for us at the apartment as agreed, and gave us a good orientation. You have to climb 3 flights of stairs with your luggage. The apartment is on two floors, with the nice living area up top and the lower, somewhat dark level containing the bedrooms and bathrooms. The location is wonderful, you can walk to Coloseum/Forum, Piazza Navona, Zoo, Spanish Steps, pretty much all the major short-stay tourist destinations except the Vatican, to which we took a taxi. Although it is close to the Trevi Fountain, the fountain is under renovation, dry and barely visible behind scaffolding. Looks like a long project.
We enjoyed being able to relax on our terrace with some prosecco and cheese after a long day of sightseeing. Don't eat at the awful restaurants that surround the Trevi and cater to exhausted tourists whose hunger overwhelms any desire for quality or value.
A few minor drawbacks: The a/c on the bedroom level does not work very well. The shower still leaks badly, as noted by a previous reviewer, and the other bathroom only has a spray attachment in the tub, without even a bracket to hang it up high. The ventilation fan in the small bathroom makes a terrible sound. There is occasionally a strong smell of disinfectant wafting into the lower floor, I think coming from outside. There is a washing machine but no dryer, so plan accordingly so that you don't end up with a load of wet laundry when it is time for you to pack up.
The only one of these that really bothered me was the a/c problem. It seemed to come and go, so we never reported it to the manager; maybe he could have done something. I'd want to check on that before staying there again in a hot month, but otherwise I would happily go back.
Another minor thing that bothered me is that we were only given one key. This always makes me nervous when I am in a rental in a foreign country. I've never lost a key yet, but if I lost one, or locked it inside the apartment, it would really throw a wrench into my vacation plans. I prefer to have two so that my wife and I can both pocket one when we leave the apartment.
Checkout was a breeze, we just left the key on the table as instructed. The manager was very nice about letting us leave our luggage in the apartment until our early afternoon train so that we could visit the Vatican that morning.