Valter's apartment is definitely one of the best places you can stay in Rome. If you were in my position, you are looking around right now, reading reviews, checking out different places and they all look surprisingly nice. Let me help you and tell you that you should choose this apartment.
First off the apartment itself is exactly how it looks on the pictures, if not better. Better of course, because once you go inside it, you realize how amazing the space is - the lighting, the colors and the rooms. Furthermore, when we arrived the place was just cleaned by a maid and it looked amazing. Everything smelled nice and was brand new.
Then, the location of it. Just outside your doorstep are two cafe's where you can get coffee or breakfast in the morning, if you don't want to prepare your own breakfast. If you do, then there are two grocery stores very close-by (3-4 min away, once you are oriented where they are). One is Conad and the other is Carrefour (express). Conad has better prices and a larger selection of items.
From the apartment, you can walk (3-4 mins) to a tram stop (in the area of Conad), where you can ride Tram 8 and reach the Center of Rome in 5 minutes. Once you are better oriented (ride the tram once), you see that if you follow the tram line by foot you can reach the center in 7-10 mins (from the apartment!).
Finally, the host was awesome. We never saw each other in person, but our communication through iMessage and phone calls was very pleasant. He definitely went out of his way to help us and answer all of our questions within minutes of me sending him the message. He even spoke with the taxi driver to tell him where to drive us.
All in all, I can't wait to visit again and stay at this AirBnB. It's good to know I always have a place to stay in Rome.