I stayed there with a friend of mine for only 1 night, but the apartment is perfectly located (15 minutes to Termini, 5 minutes to the Colosseum). I loved the place, the room is small, but big enough for two persons. There is a TV, fridge, one king bed, well equipped bathroom and a big wardrobe with everything that you may need. It is on the first floor in an old building on a lively street. The host explained us everything in details and he was extremely nice.
If I want to go back to Rome, I will stay again at Marisa's apartment.