I stayed at Cavour for a week, and would recommend it to anyone looking for a good quality budget hotel.
The Hotel is on Via Cavour, about 2 minutes walk from the main station. Although it is on a main road most of the rooms face inward - our rooms were very quiet. We had booked one double and one single room, but were in fact given two doubles. As soon as I booked (through Venere.com) I got a confirmation e-mail direct from the hotel, which was reassuring!
The hotel isn't very clearly signed, but if you look out for the signs for Argentina and Pellican it is easy enough to find (on the right, as you come from Termini)
The staff were all very friendly and helpful , the rooms clean and comfortable and the location made it easy to walk or get public transport to most attractions.
Having stayed at other 2* hotels in Italy I felt that the hotel was better than I had expected.
The rooms appear to have been redecorated recently and have air conditioning and (mine at least) a ceiling fan as well. The rooms had few 'extras' - just bed, table & chair, wardrobe, but what else is needed? The bathrooms in both of our rooms (on the top floor) had showers (no tub) - again, they were very clean, pleanty of towels were supplied and there always seemed to be plenty of hot water, although you do have to let it run a little to warm up.
We had en suite rooms but as almost all the rooms are en suite, I don't think you would have to queue if you booked a room with shared bath.
The hotel shares a building with 3 other hotels (Everest, Pelican & Argentina) and the rooms are spead over three floors. There is a (tiny) lift .
Breakfast is contenental - croissants, bread and coffee, but everything is freshly made. The hotel doesn't have it's own restaurant, but there are plenty of restaurants and trattorias close by.
Before coming, I had read reviews auggesting that the area arond Termini was a bit rough but we weren't bothered at all. Due to it's location, there are no views, and the quieter rooms look out into the light-well, which is uninspiring, but as a base for exploring Rom ethis is excellent.
I would recommend this hotel to anyone looking for reasonably priced accommodation in Rome.