We were a party of 7 adults (3 couples + 1) staying for 3 nights. We loved the apartment, it was super clean, spacious and beautiful. It had everything we needed and more (the complimentary bottle of wine was a very nice touch). There were 2 bedrooms with king size beds and 1 bedroom with queen size bed plus a double sofa bed in the lounge, and 2 bathrooms. You can actually see a part of the Colosseum from the bedroom window across the roof top! The apartment is on the fifth floor with quite a narrow lift and stairs to access.
The location is really great, only 15 min stroll to Colosseum, about 20-30 min stroll to the other main sites (Pantheon, Fountain de Trevi etc), and across the square a food store with late opening hours. It's also only 5 min walk from Termini station. Lots of little restaurants and cafes nearby too. The area felt very safe to walk at night.
Communication and checkin/checkout was smooth and efficient, and Maria and her husband were really friendly. We all loved it and would most definitely recommend the apartment!