The appartment is really lovely - I would definitly book the same place again!
Great design, well equipped and in a nice neighborhood with a lot of very good restaurants, the famous food market and a supermarket right around the corner. The metro station Piramide isn‘t far either (7 min by feet) and till Termini you only need 4 stops. Since it‘s so central in Testaccio and since there‘s a restaurant in the basement (the appartment is on the 4th floor, so you have to like steps) it was sometimes a little noisy at nighttimes, but not too bad.
The communication with the host was very nice and pleasant. He showed me the appartment, explained everything I needed and was also available by cellphone during my stay when I had questions.