I went with my daughter for a 4 night break in this hotel. It was a 'secret' hotel on Last minute.com, which means you are not told where it is until you have paid! The list of amenities described were all technically there, but as others have said, the room was very compact, mainly because this hotel used to be a convent according to the receptionist. We asked to change to a bigger room, but were told we were already in one of the biggest! What must the others be like???? Also, a very strange arrangement in the bathroom - the shower at one end of the bath with the screen at the other. Also, a heated towel rail fitted over the bath. A new modern suite & tiles though.The main drawback for us was that the 'climate control' was not working, and reception told us it is only for the summer, and just to open the window. I have come across this before in Italy, where summer does not officially start until mid June regardless of the temperature. As others have said, Rome is very noisy - sirens, cars honking, church bells, dogs, you name it and even dustbins being emptied at midnight! We had the choice between baking or being kept awake ( the noise only reduces slightly between midnight & 5am) , but fortunately had brought my earplugs with me! In fact, I slept very well, but not so my daughter.
The good points - very clean, good breakfast & smack opposite the Metro. Near the Colosseum, but not much else, but the Metro got you to the main sights.
The bad - the area not the greatest, (grafitti absolutely everywhere), small rooms (that seems par for the course in Rome though), and the lack of air con.
HOT TIP - buy a 3 day Roma pass - it gives you unlimited Metro & bus travel (but not Airort Express) plus entrance to 2 attractions and discount on others. We didn't & lived to regret it.