I would definitely recommend this for a group of 3 or 4. Its very spacious and you will not feel cramped after a long day of sightseeing. The fact that it has two bathrooms is also a plus.
What makes this a great Airbnb is the location. It is very close to the Coliseum and more importantly the metro station(~7 minute walk). There’s a very affordable and welcoming luggage storage location where you can leave your stuff after checking out and go on sightseeing. I would most likely stay here again when I visit Rome again(just not in the stifling heat of July…). Don’t forget to hydrate : )