We had a great four-night stay in Gabriele's apartment. The location was perfect, just a short walk to the Spanish steps in one direction, and Trevi fountain the opposite way. Also, the Spagna metro stop (and an even closer taxi stand) was nearby, which we used on our Vatican and Colosseum days. The apartment is surprisingly quiet, and the wooden shutters do a great job of blocking out the light for our kids' afternoon naps. Each room has a combo A/C heater. Even though the weather was warm outside (low 70s at the end of April), the apartment stayed so cool during the day that we actually turned on the heater a few nights! This would be a great place to stay during the hot summer months. Beds were firm, yet comfortable. Kitchen was small, but worked for breakfast (although a kettle would have been welcome). There is a nice little Coop grocery store the next street over for buying whatever you need. Plenty of restaurants within walking distance, of course.
Fair warning about the downstairs neighbour, he does not tolerate noises well. He came to complain to us the final evening about our kids running around all day and night. Yes, our twin toddlers sometimes ran around in the morning (never before 8) and evening (never after 10), but it was pretty ridiculous since we were out sightseeing during the daytime (with the exception of a nap). Perhaps the floors are really thin, but I got the impression that this guy just complains a lot. I still highly recommend this place, but I wanted to give any other families a head's up.