Location: from one point of view the location is perfect. To reach Termini just 15 min walk (we had very early flight so this was crucial for us get there without using public transportation). Underground station is near the apartment. Coliseum is near. Basilica di Santa Maria Maggiore is even closer (quite good guiding building). However Monti district doesn't seem to be very pleasant place, we haven't faced any problems, but it was a little bit uncomfortable to return to the apartment late at night.
Apartment: it is very light, spacious. We got everything we needed. The apartment is not as soundproof as I'd like it to be. We were able to hear everything what was happening on the street, staircase and rooms above. We found some snacks for breakfast (buns, jam and ), Italian coffee machine, coffee, sugar, a bottle of water. We were also able to control heating in the apartment, that was a small and pleasant surprise.
Host: helpful, cheerful, responding very fast to AirBnB messages. Our check-in arranged to suit our arrival time, that was very convenient and that helped us to have more time spend for wandering around Rome.