Can't really get better connected than this flat - a super quick walk to Termini station, plus lots of buses, trams, a metro station two blocks away, and a lovely 15-20 min walk to the Colloseum.
The flat is bright and clean with sunlight on three sides and a very spacious sunny roof terrace. The beds were comfy and the bathrooms are clean and well-equipped. It can be a little chilly in winter but I imagine it's amazing in the summer - it was the coldest I've ever known Rome (-3 degrees by the end of our holiday) so we got unlucky!
The flat is high up with no lift, which is ok if you're fit and healthy but something to bear in mind particularly if you have heavy luggage! Edoardo kindly helped us carry our bags up to the flat when he met us though. He also stayed in touch via Whatsapp.
The area isn't glamorous but it's safe and really accessible; if you want real Rome, not tourist Rome, it's great. Cheap friendly restaurants nearby, a huge affordable food and household market nearby, a good record shop close by and a theatre next door, and the amazing new foodhall at Termini station a few mins away too. Neighbouring San Lorenzo is great for food and bars and central Rome is easily walkable.