We spent our Christmas holidays (2008) at the Cesari hotel. The hotel is situated in the very heart of Rome - in walking distance to all the famous attractions. There are plenty of good restaurants in the area.
The first room we got was not very spacious. The walls were very thin so we could hear almost everything our neighbours said. But after one night we got a bigger and better room. All the staff we met were very friendly and very service minded.
Breakfast was good with a variety of bread, cheese, ham, fruit and juice.
There is a very nice roof terrace - must be lovely in the summer time.
Overall I would say this is the very best hotel we have ever stayed in when visiting Rome and we will definitely come back.
Negative comments: The shower cabins are covered with much mould - this should be removed or the shower cabins should be replaced with new ones.

I stayed for a week in December of 2005. The rooms were clean and pretty, and the location was right near the Pantheon. I've seen complaints about the noise on here, but I didn't notice anything. Then again, I'm from New York.

The one thing that I would do differently next time is that I would avoid getting the breakfast if I could avoid it. It was included in our package last time, so I was sort of stuck with it. The buffet was large and varied, but the quality was nothing special, and there's no reason to eat such a huge breakfast. It's especially pointless given that the wonderful coffee shop Tasso D'Oro is right nearby, and you could have some of the most amazing coffee in the world and a lovely little pastry each morning for much less than the hotel breakfast.

We recently stayed at the Hotel Cesari. I'd call it a solid 3 star hotel.
To give a point of reference it is 20 meters (60') from the Temple of Hadrian / Piazza di Pietra : http://en.wikipedia.org/wiki/Temple_of_Hadrian
We found the location great. We walked all over (to the Coliseum and Forum, Pantheon, Spanish Steps, Trevi Fountain, as well as back from the Vatican.)
Breakfast was included and was a very good spread.
We really liked the rooftop bar which has a decent amount of outdoors area. The bartender is a really congenial guy and is glad to make reservations for you or answer questions (as were all the front desk staff).
I know there were cheaper transportation options but the hotel will offer car service for 55€. Wife & I caught different flights and for both of us they were prompt with sign waiting to pick us up. We were able to confirm transportation via email with the hotel.
Room was decent sized, shower was VERY small. Rooms facing the rear of the hotel have more noise as there is a scooter parking area directly behind the property.
I would not hesitate to stay again at this property.

We stayed here for the first part of our honeymoon, and were very pleased by this hotel! The location cannot be beat! It is within walking distance from the subway (which was awesome!!) and many tourist spots like the Trevi Fountain, Pantheon and Spanish Steps. The concierge was very helpful, especially Benny, who went above and beyond to make sure we had a great trip (Excellent restaurant recommendations, booking our train tickets on line, etc). The breakfast is also pretty good in the morning. It is not the fanciest hotel by any means, but the location and service make up for it! We would definitely stay here again.