Great, great hotel. From top to bottom. Unbeatable location, excellent staff. I would never stay anywhere else while in Rome.

As others have said earlier, the location of this hotel is unbeatable. It is situated within a 30 minute walk (or short bus/cab ride) to all the major Rome attractions, including the Forum/Colosseum, The Vatican, Trevi Fountain, Spanish Steps, etc. As you walk out the front door of the hotel you are literally steps from the front of the Pantheon, and the vibrant Piazza Pantheon, which bustles with life especially on Friday/Saturday evenings (makes it pretty convenient to grab an espresso, relax listening to various street acts, and then literally walk less than 60 seconds to get to the hotel.
The service at the hotel is also excellent, particularly Mauro and Alessandra at the front desk, both of whom were helpful and very friendly.
The hotel features a lovely rooftop bar that offers a nice view and allows one to experience light breezes, which is often a relief from hot, summer days.
My biggest beef with the hotel was the size of the rooms. We had a so-called triple for my wife, son (9) and I, and we were crammed in. We couldn't even get a chair to fit for the desk , since it left no room to walk past it on the way to the bathroom. The air conditioning vents leaked (and could not be fixed) and the front desk must make changes to the temperature for you if it's more than a degree change from what you want.
The floors were pretty dirty in the room, even after the housekeeping staff cleaned it.

While these latter comments were my negatives, it should not detract one from coming here. It is a great hotel, driven by its location.

Spent 4 nights at the Senato in mid-June. Based on Tripadvisor comments I had high expectations, and was not disappointed. The location is excellent, right on the Piazza Rotunda, and athough our room (108) was located toward the front of the hotel, noise from the square was never a problem. The room was on the small side, but average for Italy, and spotlessly clean. My single complaint would be that the mattress was very hard. The bathroom was generously sized with a combo bath/shower and water pressure was excellent. Breakfast is served in a beautiful room, with hot and cold selections. We enjoyed drinks on the roof-top bar ieach evening. There is a taxi stand right across the square and a very nice market down the side street to the left of the McDonald's. Staff were very helpful and assisted us with dinner reservations. We would absolutely stay again in a heartbeat.

We stayed here for two nights - our first trip to Rome. We plan to go back just to have the experience of the hotel and surrounding areas again. This is by far my favorite spot of our 14 days in Europe. Everything about this hotel was top notch. I hesitated in writing this review because I wanted to keep this jewel to myself....