The apartment is located at a 15-20 minute walk (downhill) from Termini train and Metro station, so it is relatively easy to get to. We took a cab (only because it was raining) and the time it took thanks to traffic and one-way streets was only a little less. Recommend you walk.
Brando is an excellent host. We communicated very well before and during the stay. He was there to receive us and show us the place, including recommendations of places to go and restaurants in the area. We asked him a few things during our stay, and he responded quickly and very nicely. He even booked our 3am taxi ride back to the airport!
The apartment is located a little away from the main places you will be visiting. It's a 10 minute walk to the Colosseum, 20 minutes to Trevi (not flat) and even more to Spagna. Not a problem if you are ok with walking everywhere. It is close to Monti area with plenty of really good mid-range priced restaurants and cafes. The closest Metro station is Cavour, just a few blocks away (downhill), and there are plenty of small shops for basic needs such as water, beer and small items, as well as supermarkets less than 3 blocks away.
The apartment itself is excellent. Two big bedrooms, a fully furnished kitchen, a comfortable living room with TV (Netflix and cable TV). The bathroom is good, the shower is excellent. Centralized heating, also very comfortable. But I must say that the best feature is a small terrace that connects to the master bedroom. We didn't get to use it because of the weather but if you go during spring or summer, enjoying a glass of wine there must be perfect!
All in all an excellent place with an excellent host.