I stayed at the Ariston during last New Year's eve (from Dec 3 to Jan 4) .
Although I think this is more of a 3* rather than a 4*, I would recommend staying a this hotel. The staff is very helpful, breakfast is quite nice, wifi internet is free, and above all, the location, close to Termini Station is great to move around Rome (2 metro lines cross at this Station and the trains arriving from Fiumicino stop at Termini).
Two complaints though:
1. The room I stayed in, was really, really small (my travel case when open, prevented me from getting to the bathroom)
2. The price, because as i told before, this is more of a 3* rank. But to be honest, I don't know if you can get a better value at this location.

In brief: it was a nice stay.

I've just read the two negative posts about this hotel. I think they've got the wrong hotel.

We booked this hotel from the reservations booth at the Termini Train station. Less than 1 minutes walk away.

We we arrived the receptionist was very friendly, we even received a complimentary drink at the bar. This hotel is the boutique variety. 2 lovely sculptures in the front entrance.

The room we stayed in was on the 5 floor, it was the best room during our 10 day visit. We stayed here for 2 days. The room was very clean with a plasma TV/satelite system. Free mini bar, a massive shower it was HUGE. In fact the whole toilet was HUGE!!!. This is a truely fantastic hotel. I would recommend it to anyone. Not the best location but only 2 minutes walk to the metro, then within 2 metro stops your at the spanish steps/or trevi fountain. In fact you could probably walk to them from the hotel. There's a lovely little restaurant directly over the road from the hotel, can't remember the name but food was very nice and cheap. I would visit again. Great hotel.

Hi,
We stayed here as the first part of a multicentre trip, we landed are Rome airport and got the train to the center of Rome (Teminus), don't forget to get your tickets stamped on the station platform, the walk to the hotel from the station was short and uneventful, although the area was extremly lively, the hotel was clean and the staff friendly, the room had no view, but to be honest there were no views to be had anyway. There were free soft drinks in the room and breakfast was good, you do need to ask for speciality coffee's though, Expresso, lates etc. It is a bit of a walk to most of the attractions, although you can get the metro for 1 Euro, we walked everywhere. Overall I was happy to start my holiday here.

Ariston was perfect for an overnight before our cruise out of
Civitavecchia. We took the train from the airport. The hotel was
less than 2 blocks away. The breakfast was wonderful. The
room was small, but the TV had the BBC and CNN for watching
Olympic coverage. Sorry we did not stay there on our return
from the cruise since it is so convenient to the train station.