The location is excellent - literally next to coliseum, you will pass it every time going to the apartment - I will always take picture of it - was it my daily routine.
Apartment was on the fourth floor, and there was a small elevator available in the building. Building was secure, with a lot of restaurants around. Andrea also provided the list and advice for places to eat.
Apartment was clean, nice, with everything available - several pillows, multiple towels, small kitchen, etc. Check-in and check-out process was painless thanks to very detailed instructions from Andrea.
We walked to most places. Vatican was a bit far away, but easily accessible using Metro, and metro station (Colosseo) was less than 5 minutes walk. Termini (train station) was 2 stops away by metro, which was very convenient, since we took the train to Florence for day trip.
Overall, it was very pleasant experience, Andrea would usually respond very quickly if I had a question, and would always provide detailed instructions. I would definitely recommend to consider this apartment if you are planning to visit the Rome.