This is the PERFECT location to see Rome from. We took a taxi from Termini to the apartment and did not need any transportation again until we took a taxi to the airport four days later. We are a couple in our 40s and the walks from the apt to EVERYTHING (Colloseo, birthday cake, Forum, Vatican, Pantheon, Trastevere, Trevi, Spanish Steps) were reasonable.
The apartment was clean and nice. Perfect for a couple and probably fine for a total of 3 or 4 people if they slept on the pull out couch. There were two A/C units and a washer/spinner so we could do laundry. They were responsive via e-mail and a nice young woman met us in the restaurant below (the entrance to the apt is literally between tables in a good outdoor restaurant) with keys and a map at the appointed time. She answered all our questions.
Apt is on the 4th floor and there is no elevator, so you will be huffing with the luggage.
bring the map everywhere and plan sites to see in a given...