I have stayed at Hotel Regno twice. (2005 and 2013) I was told about this hotel by friends from London.
It is perfect for the Pantheon and Trevi Fountain, as it is in between the two, just two blocks from either one.
I emailed back and forth with Nicola and Giuseppe ([email protected]) who arranged pick up for us at the airport as well. Saved a lot of time and was nice after the flight. (I think it was 15 Euros for 4 people - 15 to 20 min ride)
I recommend getting a room with a balcony overlooking the side street or alley. After a long day of sightseeing, we would sit out on the balcony and listen to the street musicians, and sip our wine! It does not get much better than that!!! This room might have been a triple?
If you are going to be an American and actually buy a bus ticket, they sell them in that same side street not 50 feet from the front door,,,,, and the bus stops are about 20 feet to the right of the front door.
This is not the Ritz - ok!! The rooms look exactly like what they show on their site, The hotel lobby is 10' by 15' with an elevator that can only fit one person at a time with suitcase. It is a European room, with nice people, and a great location. I would go back.!
Good Luck
Ron