Location - Absolutely perfect for us, as we weren't too bothered about the Roman ruins. 1 minute to Pantheon. 5 minutes to Piazza Navone (and open top bus stop). 10 minutes to Trevi fountain. 15 minutes to Spanish Steps. Same to Vatican (or 2 minutes to bus route if you don't want to walk).
Staff - Helpful, efficient and approachable. Nothing but praise for them.
Rooms - We had a superior (= standard) and a deluxe (next level up). Both were excellent but the difference was worth the extra for the extra space/furniture and the corner windows facing two directions. Both rooms were quiet, clean, well furnished and nicely decorated. Beds were on the firm side, but that suited us. We made a point of asking for non-smoking and got them. The rooms around us were also non-smoking.
Bathrooms - Not exactly power showers (5th floor), but up to the standard of the rooms otherwise.
Breakfast - excellent quality but expensive. If you get continental breakfasts make sure you see it on the check or you'll be charged for the buffet, whether or not you get it.
Other - Charging for internet access ? No WLAN in room ? No excuse in a hotel of this standard, and even when we paid for it the speed was barely adequate for checking e-mail and tourism-related browsing.

Beautiful property in a very fascinating spot in Rome.

Our room was decently large and very quiet. Some parts of the rooms are renovated, other not so much. Overall, very good standard. Bed slighty too stiff.

What we liked most was the quiet elegance ad the atmosphere in general. Responsive staff.

A bit too expensive.

For me it's the same as the other reviewers: the location of this hotel is absolutely perfect.
The staff at reception, the concierge and the doorman are very friendly. The lobby and breakfast area look nice.
I didn't particularly like the breakfast: dry bread and too many sweet pastries. Paying EUR 25-31 for breakfast is outrageous.
My room was huge, so was the bathroom. The shower was great. Lots of space for my stuff. But... the ceiling in the bathroom could do with a renovation and not only the ceiling in the bathroom, but also in the hallways. The wallpaper is torn and the carpet is dirty.
The cleaning ladies were chatting away at 8:15 on Sunday morning, which is far too early.
If your room is next to the elevators, ask another room because you won't sleep. The elevators are old = very noisy.
I didn't pay for the room myself because I was here for business, I would have chosen a modern hotel.

Stayed there for a long weekend in January '09. First things first: the location is simply unbeatable! From our room we saw the pantheon; the busy via del corso and corso Vittorio Emmanuele were in walking distance and you could manage campo di fiori and the spanish steps by foot! The staff was very efficient, helpful (concierge gave excellent advise on restaurants) and too well meaning: the room was overheated. Unfortunately. the water pressure in the bathroom was quiet low (okay, so it was on the fifth floor) and there was no room in the bathroom to put your toiletries on. On the other hand, the beds were broad and the breakfast buffet had a lavish range.