I would highly recommend Costanza's place. The location was perfect and very walk-able, we had a short stay in Rome so this was very important. The Colosseum was about a 20 min walk whereas the Trevi Fountain and Spanish steps were only about 12-15min walk. Costanza met us before check-in to introduce us to the building and room, she offered a map of the city and her suggestions which were very helpful. She provides breakfast voucher's to a small cafe right down the street which was really good! Costanza was very easy to get a hold of and ask questions. Overall a great place to stay in Rome!