Came across this hotel during one of my previous visits and decided to try it out.
Booking was easy and flawless, pick up from the airport went like a breeze, but taking the train (direction Tiburtina/Orte) and the tram (nr 8) is just as easy.
I had the suite mansarde, which is on the first floor, right underneath the roof. It consists of two rooms over the length of the loft (two single beds in the first room, a double bed in the second room), a separate toilet and a bathroom with toilet. Excellent for family of 4/5, but not for people over 6' because of the roof. I am 5'11" and could just stand upright in the shower, so if you are taller, go for the rooms downstairs.
The hotel is very quiet, which is amazing considering it sits right in the middle of Trastevere. The staff is very friendly and courteous and the hotel offers bicycles free of charge. Riding a bike is an excellent and convenient way of exploring Rome.
The court yard is a lovely place to read a book and drink a glass of wine.
As far as real sumptuous luxury goes, this is not the Hassler, but it makes more than up for that by being friendly, peaceful and quiet, and excellently located.
How friendly? We mismanaged my booking, so I arrived one day late and left one day early. The hotel declined to charge the extra days on the ground that I had not stayed there, even though they might have let the room to someone else.
I have been to Rome more than a dozen times, but from now on this will be the hotel of choice.