Seven of my friends and I traveled to Rome together and stayed at Diego's place for three nights. I want to start off with positives: there is definitely plenty of room for 8 people to sleep and the beds are large and comfortable, except for the sixth bed, which resembles a cot more than anything else and didn't have linens. The terrace is lovely and spacious but we were in Rome on a rainy weekend, so we didn't get much use out of it.
Also, the location is incredible because of the pizzeria and cannoleria, both right around the corner and open rather late at night. When we asked Marco, the guy who checked us in for some recommendations, he just said "there are many" and left. Yelp was helpful in his place. There's a place about a 10 minute walk away called Bella Napoli that's fantastic.
The apartment is very close to the metro, so we had an easy time getting to places like the Colosseum, the Trevi Fountain, and the Spanish steps.
One of our biggest complaints is definitely the hidden charges. We saw that there were extra fees involved in the house rules, but they asked for the money in cash, in person. AirBnb says that you should never ever conduct transactions outside of the app, but the host asked us for money TWICE outside of the normal fees that we had already paid in advance. First was 84 euro in "Rome taxes" and 30 euro for a "late fee" because we arrived after 9 pm. We initially paid the 84 euro in person when we checked in because we didn't know that we could refuse to give him cash in person. Then, later on, the host also messaged us through WhatsApp and asked us to leave money on the table so that he could come into the apartment to collect the late fee, which made us very uncomfortable thinking that he might come into the apartment while we were staying there.
The wifi was pretty horrendous--it hardly connected. Additionally, I feel that I must mention that the showers had really bad water pressure. The water would get extremely hot and cold randomly throughout the shower. Both the sinks and bidets had better water pressure than the shower heads.
Finally, the keys are very difficult to use. We had three sets, but none of them seemed to make the door open on the first, second, or even third try.
Overall, great location and livable place, but be prepared for some minor to moderate inconveniences during your stay.