This is a great apartment in a cool little neighborhood north of the Colosseum/Forum. The place is very roomy, and both the bed and the sofa bed were quite comfortable. The two of us had plenty of room. The air conditioning was great to have, and the apartment was very clean and well-stocked with everything you'd need. The wifi worked very well if we were in the room with the router (there is a table and sofa in the same room), but if you move to the other side of the apartment with the bathroom and bed, you lose connection.
We were within walking distance to pretty much all of the major attractions- the Forum/Colosseum was a short walk away, and the city center was about 10-15 minutes. The Vatican is closer to a 30-40 minute walk, but the walk isn't bad as long as it's not super hot out.
The neighborhood (Monti) is a pretty cool little place- lots of little shops and restaurants to explore, and not too many cars going along the smaller streets (it was very quiet near the apartment at night, allowed for a good night's rest). The apartment had a binder that included restaurant suggestions which was a great starting point for finding where to eat. There are a lot of options!
Overall a fantastic place to stay, and I'd recommend it to anyone!