My wife and I just spent our honeymoon here, and we had a wonderful time.
The location is easy to get to. If you land at Fiumicino and take the train to Roma Termini, the apartment is just a few minutes walk.
You're also just a few minutes from a lot of restaurants, and around 15 minutes walk to the Colluseum. Good public transport links from the station, too.
The apartment is lovely. The host was communicative all the way through, and met us at the agreed time. The place is spacious with pleasant decor and good facilities. Bed and pillows were comfortable. It was *very* hot whilst we were there, and the place stayed at a reasonable temperature with minimal air con use.
The only things I would mention that are not complaints, but things to possibly be aware of. The lift up to the apartment is pretty small, so if you're bringing large suitcases then it might be a bit of a squeeze. The washing machine is also pretty small so don't expect to be doing any big loads, but honestly I was glad to have a washing machine at all.
All in all, absolutely loved the place and would recommend it to anyone staying in Rome. Thanks for a lovely stay!