Too many reasons not to stay here again but here are some of them-

The superior rooms are directly below the bar so expect lots of noise at night and early in the morning.

The rooms are terribly laid out with an open plan design so your bathroom is 2 feet from your bed and the shower is only enclosed by a curtain.

None of the english TV channels worked and we had great problems with the pay TV which showed adult films accidentally, so beware if you have children!

The location is in a very poor area of Rome and i did not feel safe walking around at night. Homeless people sat and drank cheap alcohol right outside the front door.

If i were the Radisson i would get rid of this hotel as i won't stay in any of their hotels ever again!

Very modern luxurious hotel in heart of Rome. Clean and with a touch of history built in

With shower behind the bed, with see-thru glass doors and wall to toilet/bidet, not much privacy ! That said, I've had room with shower where it should be, in the bathroom, there are, if not thrown out, also bathrooms with tubs. Shower curtains had shrinked since new, should have been replaced long ago, now almost impossible not spilling water on the floor. Room for two if you must. No chairs, only a hard-plastic chaiselounge with extremely thin cushion, not comfy at all. You are supposed to do anything in and from the bed, which has back supports. My back support was out.of-order, not possible to straighten up. Only a small shelf for toiletries over sink, this also behind bed, within room. Items had to be placed on elevated floor. TV with arabic channels, BBC World, CNN, all the Italian channels, movie channels. Also French, Spanish, Austrian channels.
When entering room there was a definite smoke smell, either from the room attendant or from former guest (we had not asked for smoke-free room). Clean. Good ventilation, no odour when we came back a few hrs later. Soap was missing, did not ask for one, (as a test), we had one next day, but only one piece to share among two persons.
Problems with key-card, we had two rooms, for one of the rooms the card did not work at all first night. For the other a very perfect insert was needed, we had to try several times before door unlocked.
Room faced station, but not overly disturbed by train or car noise. (3rd level)
OK breakfast, has been better, and somewhat inferior to other SAS Radisson hotels I've stayed with. Too noisy background music in main breakfast room, noone thought about acoustics when planned.
Hot food containers not filled up. Fried bacon rather raw. Staff could have been quicker in cleaning up used tables (personnel reduction?)
When I asked for bus departures for Fiumicino reception staff maintained there wasn't any, only to Ciampino. But last time to Rome we had bus from F which brought us to other side of Piazza dei Cinquecento, in Via Volturno. On same place as then there were timetables for deps to C and F. Staff suggested this transport was reserved for the nearby hotels there, possibly, but we were not asked, we took bus both ways last time. Bus is only half the price of Leonardo Express Train, but takes longer time. The Leonardo entrance (Termini track 25) is right around corner from hotel, from bus stop it takes 15-20 minutes walk, 10 from Termini main hall. Apart from this, efficient reception staff.
I have not seen this side of Termini as an unsafe area, are skaters dangerous? Iron gates to hotel block supposed to be closed between 0100 and 0600, did not test this, were in bed before midnight. Did not have time to try Spa. Ooutdoor pool and bar on top floor closed for season.
Seems to me they try to be first-class, but don't succed. No qualms in recommending this hotel to others but cannot give more than a 3 this time.

As a travel agency owner that has stayed in excellent Radisson city centre hotels in Paris, Amsterdam and Berlin, I was more than disappointed by the Radisson SAS Rome. I arrived for my first 2 night stay with a friend....we had requested 2 beds but when we got to the room there was one king bed. They did come and separate the beds but it seemed as if we were putting them out. We had trouble with the keys to our room and the bathtub had hot water but when we switched it to the shower we could only get cold water
On my return stay, a few days later, as I was alone, I had requested a large bed, but of course, you guessed it, when I walked into the room their were 2 totally separate beds. They did switch rooms for me, but who needs the hassle when arriving in the evening? And this after entering the lobby to find a line-up at the front desk as there was only one person working.
The hotel is very modern.....not something I have a problem with, but it was very dysfunctional. For example, getting off the elevator on any floor, it is extremely dark. The sink in the second room.....please note that I didn't say bathroom as the bathtub and/or shower is all part of a unit behind the bed, but in the room.....had nowhere to put anything.......only on the ledge about a foot off the ground. Also very poor storage space. The only seating in the room (besides the bed) is a combination chaise lounge/chair in front of the desk, an extremely hard piece of furniture with a flimsy pillow.....not inviting at all.
Lastly, service was adequate and I dealt with a number of different staff....nothing at all notable or even worthy of mention. At no time were they able to provide an adapter for my computer.