I stayed at the Hotel Art a couple nights in Rome before and after a cruise. Both times I was lucky enough to get a room on the green floor, which is easier on the eyes than the yellow or orange floors (the top floor, the blue floor, doesn't hurt the eyes); however, on both occasions my room was not ready until about 15-20 minutes after the check-in time. In the interest of full disclosure, I was traveling with a girlfriend whose room was ready (both times) prior to check-in time. Go figure.
The rooms are nice and simple, and a great size for a Roman hotel. While the lighting is less than perfect in the bedroom (there are several small lighting fixtures rather than a bright overhead) the bathroom is lighted well, and includes a hair dryer.
As a previous reviewer mentions, the hotel has hardwood floors so it can be more noisy than a hotel with carpeting, however, I thought the only noise problem was people out late in the courtyard smoking and laughing.
The temperature of the room is controlled by the Hotel, however, you can call down to the lobby to have the temperature adjusted. I had mine lowers to 23 C without issue. You may want to note if you open the windows, the air automatically shuts off.
The staff is very helpful, and very friendly. In fact, once you check in they hand you a map of Rome and circle the hotel. They are able to recommend local restaurants, and tips for taking a taxi around town. They also recommend some walking trips & guides in the city which I would definitely look into next time I am in Rome. In addition, they offer a car service for a fee which is quite comparable to other local liveries.
It is worthwhile to book a room which includes breakfast which is a very good buffet spread: many different fruits, cereal, toast, muffins and danish, several juices, bacon, eggs, sausage, salamis, cheeses, yogurts, coffee, expresso, et al.
The Hotel is located very near the Spanish Steps, however, off a side street so surprisingly quiet considering its closest to one of the busiest sites in Roma.