Very Noisy!
First about the good: the location is great - safe street, walking distance to Roma Termini, front desk staff is amazing - fast check-in and checkout, help with taxi, etc., breakfast buffet has an excellent egg station with a great cook, the room is clean and modern, pillows are good. Water station on the floor is very convenient. Fresh towels are left at the door daily (even with no disturb sign).
Now the bad: we specifically asked for a quieter room but it still was the noisiest I have ever experienced, no sound isolation between rooms - I could hear the guys next door through the wall - every word when they talked on the phone, snore, even burp, etc. The street outside gets metal clanging from deliveries to hotels and restaurants at 2-3 am and 5-6 am non-stop and the closed window does not block the noise. At 6-30 am people start walking to breakfast talking loudly in the hall. Mattress is too soft for comfortable sleep. Only one USB port to charge the phones in the room and it did not work, and front desk did not have any spare converters like in most other hotels.
Warning: In addition to a tax paid in all hotels in Rome, at checkout we learned that there is a mandatory 7 euro per night tip that we did not know about (does not matter that we already left cash tip in the room).