My family, friends and I stayed (2 couples and 2 college-aged girls) at the Albergo del Senato last June. Everyone enjoyed the hotel. The location is perfect. If you stay, ask for a room on an upper floor facing the Pantheon, it is magical late at night overlooking this ancient structure in the moonlight. Note that there is a little noise if you face the Pantheon, but it did not disturb our sleep.
If you stay, they have a very good breakfast and a fantastic rooftop bar. What we really liked was the service. They not only helped with recommendations on restaurants, made taxi arrangements for us to go to the airport, but when we had a last minute cancellation on trip home from the airline and I had to scramble to rebook, they dealt with the taxi company, ensured we had something to eat before we ran to the airport. If we go to Rome again, we would stay there again.
Enjoy Rome,
Sandy